JP4546135B2 - Radio terminal apparatus, base station, and reverse common channel random connection method in code division multiple access system - Google Patents

Description

  The present invention relates to a radio terminal apparatus, a base station, and a random access method in which a plurality of terminal apparatuses transmit data via a common channel in a code division multiple access scheme.

  More particularly, the present invention selects one of a preamble signature that can be used by a terminal device and one of an access slot that can be used as a base. The base station acquires the preamble and informs all the terminal devices whether or not the preamble has been acquired, and the terminal device transmits data according to the preamble acquisition result. By retransmitting data, unnecessary data transmission is reduced, interference signals are reduced, network efficiency is improved, and fast retransmission of only the preamble can be performed to quickly reach an appropriate power level, resulting in a time delay. The present invention relates to a random connection apparatus and method for a reverse channel (upstream) common channel in a code division multiple access system having excellent characteristics Is shall.

  The mobile communication service, whose demand is rapidly increasing, has not been activated yet. However, the mobile communication service that supports the data service has not been activated as a service form that enables voice information transmission while moving. In simple data transmission, there is an increasing demand for moving image signal reception during movement. In particular, IMT-2000 for the 3rd generation mobile communication service that supports not only audio signals but also simple data to video and can receive services anywhere in the world through internationally integrated standards. Research on (International Mobile Telecommunication-2000) is actively conducted in Japan and overseas. In addition, mobility is somewhat limited, but research for high-speed data transmission has also been conducted, and the wireless LAN presented in the IEEE 802.11 standard draft is already 2 Mbps (Mega bit per sec) data. Has been commercialized as a product that can transmit.

  In general, when performing such high-speed data transmission, the circuit switching system (circuit-switch) currently used in public switching networks and digital cellular and personal mobile communication systems uses limited channels inefficiently. So it is not desirable. The IMT-2000, which has been studied as a standard for short-distance regional networks and next-generation mobile communication systems, is a packet switching method for high-speed data transmission. (packet-switch) is applied.

  On the other hand, the CDMA (Code Division Multiple Access) signal band spreading method applied in the digital cellular system that is currently in service increases the capacity and cannot be wiretapped from the outside. It is characterized by stable communication in a multipath environment generated by a rapidly changing wireless channel.

  The IMT-2000 system, which is currently undergoing standardization activities, has the basic requirement to support packet data as well as existing voice data. However, due to the non-periodic nature of packet data, As described above, the method of using the dedicated channel has a problem that resources cannot be used efficiently. That is, continuous data such as voice data is allocated and used as a dedicated channel, whereas in the case of packet data that is discontinuous and variable in the amount of data to be transmitted, If a dedicated channel is used, there arises a problem that the capacity supported by the system cannot be satisfied.

  Therefore, if an appropriate number of reverse (upstream) channels are used in common, not only can resources be used efficiently, but voice services and services with variable amounts of data can be accommodated within the capacity of the system. can do. Furthermore, since it is expected that the amount of data transmitted by subscribers will increase in the future, efficient use of resources using the reverse (upstream) common channel should be an essential matter.

  The ALOHA method is known as the simplest method for channel connection using such reverse (upward) common channel and data transmission. The ALOHA method was developed as a typical random connection method in 1970 as a protocol for a wireless network between Hawaii islands at the University of Hawaii. In the ALOHA method, data is transmitted without a separate time plan between the base station and the terminal device, so that the data transmission efficiency is lowered. In particular, when there are many terminal devices, collisions between transmission data frequently occur. So, network overload phenomenon occurred. Therefore, in order to determine this problem, a slot ALOHA in which a standard time is set between the base station and the terminal device has been studied. In the slot ALOHA, when data to be transmitted by the terminal device is generated, data transmission efficiency is increased by allowing transmission only within the reference time. The reason is that the efficiency of the network is generally improved by reducing the probability of being disturbed by its own data transmission due to data generated in other terminal devices.

  Next, a conventional ALOHA protocol using a code division multiple access method will be described with reference to FIG.

  FIG. 9 illustrates a data transmission process in the ALOHA protocol using a conventional code division multiple access system.

  According to FIG. 9, data transmission is performed through one access attempt (access attempt) in the terminal device. This connection attempt is composed of a plurality of access sub-attempts, and this access sub-attempt is The connection probe sequence includes a plurality of access probe sequences. The connection probe sequence includes a plurality of connection probes.

  This connection probe includes a connection channel message or a preamble transmitted in the form of a simple pilot before transmission of user data, and connection information and user data following this preamble, in order to capture terminal device timing. This is done with an access message capsule.

  Through the connection attempt process configured as described above, a terminal device that intends to transmit a connection message or data through a reverse common channel first transmits one connection probe at a constant power level. The power level used at this time not only reduces the influence of interference on other terminal devices that transmit data using dedicated channels or transmit data through other reverse common channels, but also reduces the number of retransmissions. Use the best one to reduce the processing time through.

  The terminal device that attempted data transmission with the first connection probe monitors an indication as to whether or not the connection probe has been detected from the base station for a certain period of time (TA). However, if data transmission of the first connection probe fails, after waiting for an arbitrary time (RS), re-transmission is performed at a power level increased by a certain level (PI) from the power level of the first connection probe. become.

  Through such a process, the terminal device continuously attempts a connection probe including data transmission. However, if data transmission can no longer succeed within the preset number of connection probes, after terminating one connection probe sequence and waiting for another arbitrary time (RS), the terminal device performs the second connection probe sequence. It will begin in the same way as when the first connection probe is transmitted.

  Patent Document 1 also provides “a mobile communication system that significantly reduces the time required to process a random access outgoing call from a mobile device. At the time of connection setup, the mobile device (16, 18) is a preamble. A random access packet including a plurality of fields is transmitted, and the information provided in these fields is used by the base station (12) to facilitate a more efficient connection setup and allocate channel resources faster. It also provides a system for detecting, identifying and receiving a plurality of random access requests, each mobile station (16, 18) being one of a plurality of different preamble symbol patterns in a random access request packet. The base station receiver (14) includes a plurality of accumulators (126), each of which Are tuned to different preamble symbol patterns, so the base station receiver (14) can simultaneously identify multiple random access requests, which can also be used for power such as that used in IS-95 and CODIT systems. It can also be used in conjunction with gradient processing to control the power of each mobile station attempting multiple random accesses. "

International Publication No. 98/18280 pamphlet (reference patent family: JP-T-2001-502866, FIG. 3)

  However, since the ALOHA system transmits data with an appropriate power level in the contention mode, an insufficient power level between transmission data and connection probe failure due to collision cannot be avoided. A result of useless transmission failure occurs.

  On the other hand, there is also a method of using a large number of preamble signatures in order to improve the probability of capturing a preamble. The preamble signature is a sequence composed of a plurality of symbols that modulates a common spreading code used for a preamble for a reverse (upstream) common channel. Since orthogonality is maintained between the preambles, the base station can simultaneously acquire a large number of preambles with different preamble signatures.

  As long as the preamble is a signal for capturing the synchronization of the reverse common channel, more stable synchronization can be obtained if the preamble becomes longer, but this is not effective in terms of transmission efficiency.

  Therefore, an object of the present invention is to solve one or more of the preamble signatures that can be used by the terminal device and the connection slots that can be used. 1 is selected, the preamble is transmitted to the base station, the base station acquires the preamble, informs all the terminal devices whether or not this preamble has been acquired, and the terminal device acquires the preamble. Transmit data according to the result, or retransmit the preamble, reduce unnecessary data transmission and reduce interference signal, improve network efficiency and perform fast retransmission only of preamble Code division multiple access method with excellent time delay characteristics. It is to provide a device and method for randomly connecting reverse (upstream) common channels in a formula.

  Therefore, according to the reverse common channel random connection apparatus and method in the code division multiple access system according to the present invention, when the terminal apparatus transmits the preamble modulated by the preamble signature, it effectively manages various packet data. For this purpose, one preamble signature is randomly selected from a subset of preamble signatures classified according to traffic characteristics.

  In addition, the base station captures preambles for all available preamble signatures, and then reports the captured preamble signatures to all terminal devices using a forward link common channel. The transmitted terminal device can confirm whether or not the preamble sent by itself is captured (that is, whether or not it is captured). If the preamble is captured, the terminal device transmits information data to the user at a power level appropriately set according to the power level at the time of transmitting the preamble for a predetermined time. However, if the preamble is not captured, the terminal device randomly selects an access time and a preamble signature, and is increased from the power level of the previous preamble by a predetermined power step. Determine the power level and retransmit the preamble.

  In order to achieve the above object, in the random access apparatus and method for the reverse (upstream) common channel in the code division multiple access scheme according to the present invention, the base station reverses all the available preamble signatures. Preambles transmitted from a plurality of terminal devices through a common channel are captured, and a signal indicating whether a preamble signature transmitted from the plurality of terminal devices is captured (that is, whether or not it has been captured) is forward ( (Downward) transmitted to a terminal device via a common channel, and a plurality of terminal devices randomly select a preamble signature classified according to the characteristics of data to be transmitted, modulate the preamble, and transmit a common channel from the base station Received and transmitted preamble representing the preamble capture indication transmitted via When the signature is captured, the user information data is transmitted at a predetermined time at the power level appropriately set according to the power level at the time of preamble transmission, and when the transmitted preamble signature is not captured, the connection slot The preamble is retransmitted with a preamble signature selected at random.

  As described above, according to the wireless terminal apparatus, the base station, and the reverse common channel random connection method in the code division multiple access system according to the present invention, the dedicated channel is classified by classifying the preamble signature according to the data characteristics. It is possible to use various types of reverse (upstream) common channels such as channel request for allocation, packet access for transmitting short data, and medium size data.

  In addition, the present invention reduces unnecessary data transmission and interference signals, improves network efficiency, and retransmits in units of preambles so that it can quickly approach an appropriate power level and has excellent time delay characteristics. Obtainable.

  Hereinafter, a reverse connection (upward) common channel random connection apparatus in the code division multiple access system according to the present invention will be described with reference to the drawings.

  FIG. 1 is a network configuration diagram of a general code division multiple access system for applying the present invention. The network generates a data and transmits a preamble data through a reverse (upstream) common channel, and a code capture using the preamble transmitted from the terminal 100 via a reverse common channel. To notify the terminal device 100 whether or not the preamble has been captured, receive corresponding user information data from the terminal device, and manage the base station 200 linked to the upper layer protocol and the plurality of base stations 200 and 210. A CDMA network 300 linked to other networks, a PSTN (Public Switched Telephone Network) 400 that links the terminal device 100 and a general telephone subscriber linked to the CDMA network 300, and a terminal device 100 linked to the CDMA network 300. And Internet users And Tsu (500) is constituted by a PSDN (Public Switched Data Network) 600 combining data server in conjunction with the CDMA network 300 receive the support of the terminal apparatus 100 and the data service.

  In the network configured as described above, the reverse connection (uplink) common channel random connection apparatus includes an acquisition indication signal transmission means in the base station, and the acquisition indication signal reception means in the terminal apparatus. And transmission determining means.

  The transmission means of the base station 200 determines whether or not it has captured the transmitted preamble signature after the preamble code acquisition has been performed on all available preamble signatures via the reverse (upstream) common channel. The captured display signal to be displayed on the terminal device is transmitted. The receiving means of the terminal device receives the captured display signal from the base station via the forward (downward) common channel, and the determining means of the terminal device transmits user information data by the captured display signal or retransmits the preamble. Decide whether to transmit.

  If it is displayed that the preamble signature has been captured, the terminal transmits user information data, otherwise the preamble is selected with a randomly selected preamble signature and increased power in the newly selected connection slot. Transmit again.

  FIG. 2 is a functional block diagram of a terminal apparatus and a base station in a reverse connection (upstream) common channel random connection apparatus according to the code division multiple access system according to the present invention.

  The terminal device 100 randomly selects one of the available preamble signatures classified according to traffic characteristics and a connection slot to transmit, and forward path loss, interference signal reported from the base station A first terminal determining unit 110 that determines the power of the preamble using a level and the like, and a first terminal that generates and transmits a preamble signal with the preamble signature and power level in the connection slot selected by the first terminal determining unit 110 The transmission unit 120, a terminal first processor 170 that formats user information data activated and transmitted by the terminal first determination unit 110, and a user information signal formatted from the terminal first processor 170 are input. Chan corresponding to the preamble signature A terminal second transmission unit 180 that performs band spreading to a channelization code, and outputs a preamble signal generated by the terminal first transmission unit 120 according to an acquisition display signal transmitted from the base station 200, 2 a terminal selection unit 130 for selecting one of the data generated by the transmission unit 180, and a signal selected by the terminal selection unit 130 is converted into an RF signal and transmitted to the base station 200 through a radio channel. The terminal second processor 140 that converts the capture display signal of the RF signal transmitted from the base station 200 into a baseband signal, and the preamble signature that is transmitted when the baseband capture display signal is input from the terminal second processor 140 is captured. Terminal reception unit 150 for confirming whether or not the transmission preamble signature is confirmed by terminal reception unit 150 The terminal first determining unit 110 is enabled / disabled I, and a terminal second determination unit 160 for outputting a signal for switching the switch of the terminal selection unit 130.

  As illustrated in FIG. 3, the terminal first determination unit 110 receives and stores information on preamble signatures classified according to traffic characteristics transmitted from a base station via a forward (downlink) common channel. Select a preamble signature by a random method from the available preamble signatures corresponding to the traffic characteristics by classifying the characteristics of the data generated in consideration of the traffic characteristics and the requirements in the upper layer with the storage unit 111 Signature selection unit 112, and when a preamble is transmitted, randomly or deterministically, a slot selection unit 113 that selects a connection slot, an interference signal level of a base station, and a forward direction (downlink) ) Consider path loss and previously transmitted preamble power level And a power determination unit 114 that determines the power of the preamble to be transmitted.

  The power determination unit 114 includes a base station interference signal level transmitted from the base station via a forward (downward) common channel, a forward (downward) path loss, a predetermined power increase step, The power level is determined in consideration of the power level of the preamble.

  Referring back to FIG. 2, the terminal first transmission unit 120 uses the connection slot, preamble signature, and power level determined by the terminal first determination unit 110 to generate a common spreading code according to the preamble signature. A preamble is transmitted by modulation, and a complex band spread signal having a real value identical to an imaginary value is generated using the selected preamble signature and common band spreading code.

  The terminal receiving unit 150 receives the capture display signal using a signature that is the same as the transmitted preamble signature and the code used for capture display transmission on the forward link.

  In addition, the terminal second determining unit 160 enables the terminal first determining unit 110 to indicate that the preamble signature transmitted by the captured display signal received by the terminal receiving unit 150 is captured, and the terminal selecting unit 130 and the terminal A signal for combining the outputs of the first transmission unit 120 is generated. On the other hand, if not, the terminal first determination unit 110 is disabled and the output of the terminal second transmission unit 180 is sent to the terminal selection unit 130. Combine.

  The base station 200 receives the RF signal transmitted from the terminal apparatus 100, and base station the base station processor 210 that transmits the RF signal to the terminal apparatus 100 and the preamble transmitted from the terminal apparatus 100 via the reverse common channel. A base station synchronization unit 220 that performs acquisition of this preamble with all available preamble signatures input from the station processor 210; a base station determination unit 230 that determines and outputs a preamble signature that is captured by confirming the acquisition; A base station transmission unit 240 that generates a plurality of acquisition display signals corresponding to the acquisition preamble signature input from the base station determination unit 230 and outputs the acquired acquisition display signals to the terminal device 100 via the base station processor 210; Base station determination unit receiving multipath time delay information acquired by station synchronization unit 220 30 is used to generate a despreading code using information on the captured preamble signature received from 30 and receive data transmitted from the terminal device 100 via the reverse common channel from the base station processor 210 and perform demodulation and channel decoding. It comprises a base station transceiver 250 that performs transmission and the like.

  The base station synchronization unit 220 receives a preamble transmitted from the terminal device 100 through the reverse common channel by the base station processor 210 and acquires a preamble with all available preamble signatures, and a captured preamble. A time delay characteristic output unit that causes the base station transceiver 250 to recognize all the time delay characteristics corresponding to the signature and prepares the transceiver 250 to receive data to be transmitted at an arbitrary predetermined time; and a base station determination unit And an output unit that outputs a capture display signal that reports the preamble signature captured at 230.

  The base station determination unit 230 notifies the base station transceiver 250 of a band spreading code corresponding to the preamble signature received from the base station synchronization unit 220 and prepares to receive data transmitted immediately at a predetermined time. The generation unit and an acquisition display signal generation unit that generates an acquisition display signal corresponding only to the captured preamble signature and outputs this signal to the base station transmission unit 240.

  The base station transmission unit 240 divides the available time by the number of available signatures, assigns the time obtained by the division to each available preamble signature, and is assigned to the captured preamble signature. On-off signal format (# 1) that transmits the captured display signal only at the time and does not transmit the captured display signal at the time assigned to the preamble signature that was not captured, and the number of signatures that can use the available time Divide by and assign each divided time to each available preamble signature, and a positive capture indication signal for the preamble signatures captured for all divided times assigned to the available preamble signatures. For preamble signatures that were transmitted and not captured An antipodal signal format (# 2) for transmitting a negative capture indication signal and an orthogonal symbol corresponding to the captured preamble signature by assigning an orthogonal code to the preamble signature and setting it as a symbol to be transmitted Only the on-off signal format (# 3) that transmits only the orthogonal signature is assigned to the preamble signature and the symbol is set to transmit, and a positive capture indication signal is transmitted for the captured preamble signature and not captured. The preamble signature is configured to transmit an acquisition display signal based on any one of the antipodal signal formats (# 4) for transmitting the negative acquisition display signal. It is also possible to combine four signal formats to create another signal format for use.

  The acquisition display signal transmission system includes a puncturing method applied to the forward common channel used in the existing method, a method using a code having orthogonality in the forward common channel, and orthogonality to the forward common channel. Any one of the methods using a code having no symbol is selected and transmitted.

  In addition, the base station 200 assigns a dedicated channel for transmitting packet access for transmitting short data, a channel reservation request for transmitting intermediate data, and large continuous data such as voice data. The channel request for requesting the data classifies the nature of data transmitted through the reverse common channel. Then, the base station 200 classifies all possible preamble signatures according to the nature of the data to be transmitted, and broadcasts them through the forward common channel so that all terminal apparatuses can recognize them.

  In order to access the packet to the base station 200, the terminal apparatus 100 uses one preamble signature among preamble signatures divided by data characteristics such as the length of data to be transmitted through packet access and the transmission rate. , And considering whether to display the preamble transmitted from the base station 200 and determine whether to retransmit the preamble or transmit user information data. If user information data is transmitted, single or multiple frames that conform to the frame structure are continuously transmitted, and packet access operation is performed for frames that have failed to be transmitted among the transmitted frames. Do again.

  For the channel reservation request, the terminal device 100 randomly selects one of the preamble signatures assigned for the channel reservation request and transmits the preamble in the same manner as packet access. The transmitted preamble is captured and the captured preamble is notified to all terminals through the forward common channel. When the terminal device 100 displays a negative capture display or no capture display, the terminal device randomly selects one of the preamble signatures assigned for channel reservation, determines a connection slot, and determines the preamble. When the terminal device 100 transmits the preamble in which the preamble signature is captured, the user information data for the reservation request is transmitted and the channel reservation data is transmitted to thereby reserve the channel. . In the base station 200, after correctly receiving the data transmitted for the channel reservation from the terminal device, the channel reservation status (that is, whether or not the reservation is possible) using the forward (downward) common channel and the reserved time and The corresponding terminal device is notified of the spreading code and the transmission rate, and the corresponding terminal device transmits the data to be transmitted using the reserved time, the spreading code and the transmission rate, and forward ( Closed loop power control is performed using a power control command transmitted in the (downward) channel. Then, when transmitting the final frame, the terminal device transmits information indicating that the data transmission is completed together with the data to cancel the channel reservation.

  One method for changing channel reservation conditions during reservation is a method in which the terminal device 100 transmits data for changing channel reservation conditions together with data transmission in the same manner as an operation for packet access or channel reservation request. There is. The other method is a method in which the terminal device 100 multiplexes data for changing channel reservation conditions together with user information data and transmits the multiplexed data. In both ways, the base station 200 must transmit information related to acceptance or rejection.

  The operation of the reverse connection (upstream) common channel random connection apparatus in the code division multiple access system according to the present invention will be described below.

  FIG. 4 is a schematic diagram for explaining the operation between the terminal apparatus and the base station in the random access apparatus according to the present invention.

  FIG. 4 will be described. When data to be transmitted is temporarily generated, the terminal device 100 transmits a preamble to the base station 200, and the base station 200 acquires a preamble code and transmits an acquisition display signal for preamble code acquisition to all the terminal devices 100. As a result, each terminal apparatus 100 monitors the captured display signal, retransmits the preamble when the transmitted preamble is not captured, and transmits user information data when the transmitted preamble is captured. . The base station 200 that has received the data receives the user information data, and transmits an acknowledgment signal of the user information data to the terminal device 100 after the error check. The time that the preamble did not capture is called idle time (IT).

  As shown in FIG. 5, when the data to be transmitted is generated (S101), the terminal device 100 operates as one of the available preamble signatures corresponding to the traffic characteristics in order to transmit the preamble. A connection slot is randomly selected (S102), and a step (S103) of determining the power of the preamble to be transmitted using information on the forward path loss, the interference signal level transmitted from the base station 200, and the like is performed. Next, a preamble is generated and transmitted using a randomly selected preamble signature and a determined power level in a randomly selected connection slot (S104).

  Then, the terminal device 100 receives the preamble capture display signal broadcast from the base station 200 to all the terminal devices 100 (S105), and checks whether the preamble signature transmitted by itself is captured (S106).

  If the preamble transmitted by itself is captured in the process of receiving the captured display signal, the terminal device 100 formats the user information data in a predetermined format, performs data transmission for selecting a message or a preamble, and generates a preamble signature. Data transmission is performed in which the corresponding specific spreading code is spread and transmitted (S107), and if the preamble transmitted by itself is not captured in the reception process of the captured display signal, the terminal device can determine the preamble signature, connection slot, power level. The steps starting from the transmission resource determination step are repeated and the preamble is retransmitted (S108).

  On the other hand, the base station 200 controls transmission of a preamble capture display signal as illustrated in FIG. First, the base station 200 receives an RF signal at a terminal device (S201), and acquires a preamble code in order to acquire synchronization for the preamble with all available preamble signatures (S202). Next, the base station confirms whether the preamble has been captured, determines the captured preamble signature (S203), generates a captured display signal corresponding to the captured preamble signature, and transmits this to all terminal devices (S204). ).

  The base station 200 acquires the multipath time delay information and fading phase information acquired in the preamble code acquisition step, generates a despread code using the acquired preamble signature information, and prepares for reception ( In step S205, the terminal device receives data transmitted through the reverse common channel, and receives user information data through demodulation and channel decoding processes (step S206).

  The above operation will be described in more detail. When the terminal first determination unit 110 is enabled from the outside, one preamble signature is randomly selected from a set of preamble signatures classified according to the characteristics of data transmitted by the enabled terminal first determination unit 110 and connected simultaneously. A slot is also selected at random. Next, the first terminal transmission unit 120 generates a preamble that spreads and transmits the preamble signature using the common band spreading code, and transmits the preamble in the selected transmission slot. At this time, the terminal selection unit 130 is coupled to the first terminal transmission unit 120 and outputs the preamble from the second terminal processor 140 to be transmitted to the base station 200.

  As a result, in the base station 200, the base station processor 210 receives the preamble transmitted from the terminal apparatus 100 and outputs the preamble to the base station synchronization unit 220. The base station synchronization unit 220 uses the preambles for all usable preamble signatures. The code acquisition is performed and information regarding the acquisition is output to the base station determination unit 230. Then, the base station determination unit 230 determines a preamble signature obtained by receiving information about each preamble signature from the base station synchronization unit 220 and outputs it to the base station transmission unit 240 and the base station transceiver 250. Next, the preamble signature captured by the base station transmission unit 240 is received, a signal corresponding to the captured preamble signature is generated, and the signal is output to the terminal apparatus 100 through the base station processor 210 using the forward common channel. At the same time, the base station transceiver 250 receives the preamble signature captured from the base station determination unit 230 and prepares to receive data transmitted from the terminal apparatus 100 using a band spreading code corresponding to the captured preamble signature. .

  Meanwhile, the terminal receiving unit 150 receives the captured display signal transmitted from the base station 200 through the forward common channel via the terminal second processor 140 and confirms whether the transmitted preamble is captured. Is output to the terminal second determination unit 160.

  At this time, when it is confirmed that the preamble transmitted by the terminal second determination unit 160 is successfully captured, the determination unit 160 disables the terminal first determination unit 110 and the terminal first transmission unit 120, and the terminal second transmission unit. 180 spreads the user information data formatted by the band spreading corresponding to the preamble signature transmitted by the terminal first processor 170 and outputs the user information data to the terminal selection unit 130. The terminal selection unit 130 receives the preamble signature capture display signal from the terminal second determination unit 160, closes the switch to the terminal second transmission unit 180, and transmits the signal to the base station 200 through the terminal second processor 140. It will be. Then, the transmitted data is input to the base station transceiver 250 through the base station processor 210, and the base station transceiver 250 uses the band spreading code previously confirmed through the reverse common channel to perform the data through demodulation and decoding processes. Will be restored.

  On the other hand, when the terminal second determination unit 160 confirms that the transmitted preamble signature is not captured, the terminal first determination unit 110 and the terminal first transmission unit 120 are enabled. That is, terminal first determination section 110 selects one new preamble signature at random from the set of preamble signatures, and at the same time selects a connection slot either randomly or deterministically.

  Similar to the initial preamble transmission, the first terminal transmission unit 120 generates a preamble that spreads and transmits the preamble signature determined using the common band spreading code, and transmits the preamble in the selected connection slot. Let At this time, the terminal selection unit 130 is connected to the terminal first transmission unit 120, outputs the preamble to the terminal second processor 140, and transmits this preamble to the base station 200. The operation and the like are repeated with a limited number of repetitions, and the number of repetitions depends on the balance of the traffic loaded in the system and other system conditions.

  FIG. 7 shows an example of the operation of the reverse connection (uplink) common channel random connection apparatus in the code division multiple access scheme.

  First, as shown in FIG. 7, assuming that the frame period is 10 ms and one slot is 1.25 ms, there are eight connection slots in one frame period, and one preamble is 1 ms. Will be occupied. Therefore, the connection slot is composed of a preamble duration of 1 ms and an idle time (idle time) of 0.25 ms. In the base station 200, the connection slot is configured with a capture display signal duration of 1 ms and an idle time of 0.25 ms. Also, for simplicity of explanation, only the case where there are two preamble signatures within one frame duration and only short data is available is considered.

In FIG. 7, it is assumed that data transmitted before the first connection slot start time (T ₀ ) is such that three terminal devices out of a certain terminal device randomly select a transmission slot identical to a certain preamble signature. At this time, the base station 200 has no preamble to catch, and this is because there is no preamble having a sufficient power level. At this time, the base station 200 transmits only the negative captured display signals of the signal formats # 2 and # 4 and the uncaptured display signals of the signal formats # 1 and # 3. Therefore, each terminal apparatus must be randomly selected or retransmit each preamble with a preamble signature randomly selected in a predetermined connection slot and an increased power level.

Terminal device determines a sufficient power level by open loop power control (open loop power control), in the next connection slots T _1, and transmits each preamble another preamble signatures. All two preambles are well captured and a positive or on-acquisition indication signal is received at all terminals. Therefore, the terminal device for 10ms in connection slot T _2, will transmit the user information data. Of course, access time of data transmission may extend T ₃ or T _4.

Even in the time slot T ₂ , the two terminal apparatuses may transmit the preamble with the same preamble signature, and the base station may succeed in acquiring the preamble code synchronization. Therefore, the two terminal devices receive a positive or on-capture display signal corresponding to their own preamble signature, and transmit their user information data at a predetermined time. In this case, if all the power levels such as the captured preamble are sufficient for the base station to acquire the preamble code, the base station transmits the user information because the receiver synthesizes the multipath signal from other user information data. The data cannot be received successfully. However, if only one preamble has a sufficient power level, the receiver of the base station can synthesize the multipath signal of only one user information data at a sufficient power level and succeed in demodulating the user information data. It is possible to decrypt.

  FIG. 8 shows an example of the interference signal level of the reverse common channel apparatus according to the present invention. The level indicated by the solid line in FIG. 8 is the interference level of the conventional arbitrary connection device of the reverse common channel, and the level indicated by the broken line is the interference signal level of the random connection device of the reverse common channel according to the present invention. The hatched portion indicates the amount of decrease in the interference signal level due to the reverse common channel random connection apparatus according to the present invention as compared with the prior art.

  As can be seen from FIG. 8, the reverse common channel arbitrary connection apparatus according to the present invention reduces the interference signal level by suppressing a large amount of unnecessary data transmission, and increases the overall capacity, Since the influence on users using other channels can be minimized and retransmission can be performed in units of preambles, faster data transmission is possible.

  Next, a short data transmission service of various sizes will be described using an operation similar to the above-described operation. At this time, if the data length exceeds the predetermined level, a dedicated channel or reservation request is required, so the length of data accepted by the arbitrary connection method is an integral multiple of the existing frame unit, and the type Is also restrictive. For example, if the random connection method can accommodate data whose length is four times the frame length, the terminal device must request a dedicated channel allocation or a reserved channel for data whose length exceeds four times the frame length. .

  At this time, first, the preamble signature assigned for the packet access in the base station must be classified according to the data length and recognized by all terminal devices. By doing so, it becomes easy to dynamically assign the preamble signature while considering the traffic balance due to the length of other data.

  When the terminal device attempts to transmit data on the reverse common channel, these determine data traffic characteristics such as the length of data to be transmitted and the transmission rate. If the terminal device intends to transmit data via the random connection method and device according to the present invention, the preamble is transmitted with the preamble signature, and the message signal including the data is transmitted by the capture display. If the terminal device attempts to transmit data through a dedicated channel or a reserved channel, it transmits a preamble with a preamble signature and transmits a message signal for requesting a dedicated channel or a reserved channel based on a captured display signal. For example, if the terminal device attempts to transmit 40 ms data using the random connection method and device, the terminal device transmits the preamble using one of the preamble signatures assigned to the 40 ms data, and configures four 10 ms frames. The frames are transmitted continuously. And if one of the continuously transmitted frames fails to be transmitted, only one is retransmitted. At this time, the terminal device selects a new preamble signature assigned to the data characteristic to be retransmitted by the same method as described above, and transmits the preamble and the message signal.

  Next, an operation for requesting channel reservation using a reverse common channel when a terminal device needs to temporarily reserve a channel to transmit intermediate length data will be described.

  That is, if the base station 200 correctly receives data for channel reservation, the base station 200 notifies the corresponding terminal device of the channel reservation, the reserved time, the spreading code, the allowable maximum transmission rate, etc. Data is transmitted within the maximum allowable transmission rate by using a band spreading code at the time when the terminal device receiving this is reserved. At this time, the base station 200 transmits a power control command signal (Power Control Command) using the forward common channel or a dedicated channel to the reserved terminal device to perform closed loop power control.

  When the terminal device intends to change the channel reservation condition during the channel reservation, data related to the channel reservation condition to be changed is transmitted in the same manner as the method of transmitting the preamble for the initial channel reservation. . Also, when the current transmission rate is lower than the maximum allowable transmission rate, the current message transmitted with data related to the channel reservation condition to be changed can be multiplexed. When the channel reservation is completed, the terminal device piggybacks completion information in the last predetermined field and transmits it to the base station. The base station 200 releases the reserved channel and time, This is notified to all terminal devices.

  The above-described method for reserving channels of intermediate length data can also be used in application fields such as packet voice services where services are expected in the future.

  On the other hand, when the transmission data is long or a dedicated channel is required for servicing the audio signal, a method similar to the above-described channel reservation is used. First, the terminal apparatus randomly selects one of the preamble signatures assigned for the dedicated channel and transmits the preamble, and receives the acquisition display signal for acquiring the preamble code from the base station 200 to request the dedicated channel. The data will be transmitted. Then, after the terminal device is informed of whether the dedicated channel is allocated (that is, whether allocation is possible) and information on the band spreading code, etc., the terminal device transmits / receives data using the dedicated channel. Also in this case, unlike the channel reservation request (that is, the preamble is transmitted by selecting one of the preamble signatures assigned for channel reservation), the terminal device is not limited by the frame length. Can transmit data. In addition, since one or more dedicated channels are assigned to all of the reverse direction and the forward direction, the closed loop power control can be easily implemented.

  Although the preferred embodiments of the present invention have been illustrated and described above, various changes, modifications, etc. can be made. The detailed description does not limit the scope of the invention, which is defined by the claims.

It is a figure which shows the network structure of the code division multiple access system to which this invention is applied. It is a block diagram which shows the structure of the terminal device and base station in the random connection apparatus of a reverse direction common channel by the code division multiple access system concerning this invention. It is a block diagram which shows the structure of the terminal 1st determination part 110 of FIG. It is explanatory drawing for demonstrating the operation | movement between the terminal device and base station in the random connection apparatus by this invention. It is a flowchart which shows an example of the connection control procedure of the terminal device by this invention. 5 is a flowchart illustrating an example of a connection control procedure of a base station according to the present invention. It is a figure for demonstrating operation | movement of the random connection apparatus of a reverse direction common channel by the code division multiple access system concerning this invention. It is a figure which shows an example of the interference signal level by a reverse direction common channel by the code division multiple access system concerning this invention. It is a figure showing ALOHA data transmission using a reverse direction common channel by the code division multiple access system by a prior art.

Explanation of symbols

100 terminal device 110 terminal first determination unit 111 signature storage unit 112 signature selection unit 113 slot selection unit 114 power determination unit 120 terminal first transmission unit 130 terminal selection unit 140 terminal second processor 150 terminal reception unit 160 terminal second determination unit 170 Terminal first processor 180 Terminal second transmission unit 200 Base station 210 Base station processor 220 Base station synchronization unit 230 Base station determination unit 240 Base station transmission unit 250 Base station transceiver

Claims (32)

In a wireless terminal device that transmits data to a base station using a code division multiple access method,
Preamble generating means for generating a preamble signal using one preamble signature randomly selected from a plurality of available preamble signatures classified according to traffic characteristics ;
Data generating means for generating data for transmission;
Preamble transmission means for transmitting only the preamble signal generated from the preamble generation means using a randomly selected connection slot to the base station via a reverse common channel;
In response to an acquisition indication signal representing acquisition of the transmitted preamble signal received from the base station via a forward common channel, the data is transmitted to the base station, or another preamble signal is retransmitted. And a transmission control means for controlling the wireless terminal device to control the wireless terminal device.   When the transmission control means does not receive the acquisition indication signal, the transmission control means selects a new preamble signature in the preamble generation means, and uses the selected new preamble signature in the selected one preamble signature. The radio terminal apparatus according to claim 1, wherein the preamble is transmitted at a time already set in the base station.   The radio terminal apparatus according to claim 1, wherein the preamble is transmitted using a connection slot randomly selected from available connection slots. The preamble generating means includes
Under the control of the transmission control means, the selected one preamble signature corresponding to traffic characteristics and a slot to be transmitted are randomly selected, and a forward path loss, an interference signal level transmitted from the base station, and the like are used. Terminal first determining means for determining the power of the preamble to be transmitted,
4. The radio terminal apparatus according to claim 3, further comprising: a terminal first transmission unit that generates a preamble signal using the transmission slot, preamble signature, power level, and the like determined by the transmission resource determination unit.   The transmission control means is a transmission for selecting a signal to be transmitted from the preamble generated by the preamble generating means and the data generated by the data generating means in response to an acquisition display signal transmitted from the base station. The radio terminal apparatus according to claim 1, further comprising a signal selection unit. The data generating means includes
A terminal first processing unit which is enabled by checking whether data transmission is performed from the transmission determining unit, and which matches the mode of transmitting data to be transmitted;
And a terminal second transmission unit that receives data to be transmitted from the terminal data processing unit, selects a code corresponding to a preamble signature, spreads the band, and outputs the spread to the transmission signal selection unit. The wireless terminal device according to claim 5. The terminal first determination means includes
Signature receiving means for receiving and storing information on a preamble signature assigned according to traffic characteristics, transmitted from the base station via a common channel;
Signature selection means for classifying traffic characteristics in consideration of the characteristics of generated data and higher-level requirements, and selecting a preamble signature randomly from the corresponding preamble signature;
A connection slot selection means for selecting a randomly transmitted slot;
Power determining means for determining the power of the preamble to be transmitted according to a preset reference in consideration of the interference signal level of the base station, the forward path loss, the previously transmitted preamble power level, etc. The radio | wireless terminal apparatus of Claim 4 characterized by the above-mentioned. In a base station that receives data from a wireless terminal device using a code division multiple access method,
A preamble signal transmitted from the wireless terminal device through a reverse common channel, and generated using one preamble signature randomly selected from a plurality of available preamble signatures classified according to traffic characteristics Preamble signature acquisition that receives a preamble signal , checks whether a preamble signature has been acquired, generates an acquisition confirmation signal corresponding to the acquired preamble signature, and outputs the acquisition confirmation signal to the wireless terminal device via a forward common channel Means,
Base station data transmitting / receiving means for receiving data transmitted from the wireless terminal device using a despreading code generated using the preamble signature captured by the preamble signature capturing means; . The preamble signature capturing means includes:
Base station synchronization means for receiving a preamble transmitted via a reverse common channel from the terminal device and performing initial synchronization according to all available preamble signatures;
A base station and a transceiving means for informing the base station data transmitting / receiving means of the total time delay characteristic corresponding to the captured preamble signature and preparing to receive the data to be transmitted immediately;
The base station according to claim 8, further comprising acquisition display signal output means for outputting the acquired preamble signature. The preamble signature capturing means includes:
Band spread code generating means for informing the data transmitting / receiving means of the corresponding band spreading code using the captured preamble signature, and preparing to receive the data to be transmitted immediately;
The base station according to claim 9 , further comprising acquisition display signal generation means for inputting the acquisition preamble signature from the acquisition display signal output means and generating the acquisition confirmation signal representing the acquisition preamble signature. . The capture display signal output means sets a corresponding time in a preamble signature and outputs a capture display signal as an on-off signal system that transmits a capture display signal only during a time corresponding to the capture preamble signature. The base station according to claim 9. The capture display signal output means outputs a capture display signal as an opposite signal system that sets a corresponding time in a preamble signature and always transmits a capture signal at a time corresponding to all preamble signatures regardless of capture. 10. The signal system according to claim 9, wherein the opposite signal system is a signal system in which an acquisition display signal for a captured preamble signature and an acquisition display signal for an unacquired preamble signature are opposed to each other. base station.   The capture display signal output means outputs a capture display signal as an on-off signal system in which a corresponding orthogonal code is assigned to a preamble signature and set by a symbol to be transmitted, and only the orthogonal code corresponding to the capture preamble signature is transmitted. The base station according to claim 9. The acquisition display signal transmission means sets the symbol to be transmitted by assigning a corresponding orthogonal code to the preamble signature, and sets the acquisition display as an opposite signal system that always transmits symbols corresponding to all preamble signatures regardless of acquisition. The anti-signaling system is configured to output a signal, and the capturing signal for the captured preamble signature and the capturing display signal for the unacquired preamble signature are opposed to each other. The base station according to claim 10. In a random connection method in which a plurality of terminal devices transmit data using a code division multiple access method,
In each terminal apparatus, when data to be transmitted is generated, each of the terminal signatures randomly selects a preamble signature and a connection slot, and transmits only each preamble to the base station via a reverse common channel. Wherein the preamble signature is selected from a plurality of available preamble signatures classified according to traffic characteristics ;
In the base station, initial synchronization is performed on all preamble signatures transmitted from the terminal apparatus, and a preamble capture confirmation signal corresponding to the captured preamble signature is generated to all terminals through the forward common channel. A terminal-to-terminal transmission step of transmitting;
In the terminal apparatus, in response to an acquisition confirmation signal received from the base station through a forward common channel , the terminal apparatus transmits the data to the base station or retransmits another preamble. A reverse common channel random connection method in a code division multiple access system. In the transmission to base station, when data to be transmitted is generated, the terminal device randomly selects a preamble signature corresponding to traffic characteristics and a connection slot for transmission in order to transmit a preamble, and is already set. A transmission resource determining step for determining the power of a preamble to be transmitted by the above method;
16. The preamble transmission step of generating and transmitting a preamble signal using the transmission slot, preamble signature, power level, and the like determined in the transmission resource determination step in the terminal apparatus. A method of randomly connecting reverse common channels in the described code division multiple access system. The transmission resource determining step includes:
In the terminal device, a signature information receiving step of receiving and storing information on a preamble signature assigned according to traffic characteristics transmitted from a base station through a common channel;
In the terminal device, in consideration of the characteristics of the generated data and the requirements in the upper layer, a traffic characteristic determination step for classifying the traffic characteristics;
In the terminal device, a preamble signature selection step of randomly selecting one of the available preamble signatures;
In the terminal device, a connection slot selection step of randomly selecting a connection slot for transmission at random;
The reverse connection common channel random connection method in the code division multiple access method according to claim 16, further comprising: a power determination step of determining power of a preamble to be transmitted by open loop power control in the terminal apparatus. . The already set method takes into account the interference signal level of the base station transmitted from the base station via the common channel, the forward path loss, the power level transmitted from the preamble, etc. in the terminal device. The method of claim 16, wherein the power level is adjusted by an amount that has been set. The base station transmission step uses the transmission slot, preamble signature, and power level determined in the transmission resource determination step to spread a preamble signature using a common band spreading code in the terminal device. The random connection method of a reverse common channel in the code division multiple access method according to claim 16, wherein transmission is performed. The base station transmission step includes:
The reverse connection common channel random connection method in the code division multiple access method according to claim 19, wherein the terminal apparatus generates a complex band spread signal using two common band castle spreading codes. The said retransmission step receives the acquisition display signal in the said terminal device using the code | cord | chord corresponding to the code | cord | chord used for the forward common channel, and the transmitted preamble signature, The signal of Claim 15 characterized by the above-mentioned. Random connection method for reverse common channel in code division multiple access.   The terminal apparatus in which a preamble signature transmitted by itself is not captured, wherein the step of transmitting to the base station, the step of transmitting to the terminal, and the step of retransmission are repeated a predetermined number of times. A random connection method of reverse common channels in the described code division multiple access system. The terminal-to-terminal transmission step includes:
In the base station, an initial synchronization step of performing initial synchronization according to all available preamble signatures by receiving a preamble transmitted from the terminal device via a reverse common channel;
In the base station, a determination step of confirming whether the initial synchronization is performed from the initial synchronization step, and determining and outputting an acquisition preamble signature;
In the base station, an acquisition display signal corresponding to an acquisition preamble signature input from the determination step is generated, and an acquisition display signal transmission step of outputting to the terminal device;
In the base station, multipath time delay information acquired in the initial synchronization step is input, a despreading code is generated using information on an acquisition preamble signature input from the determination step, and a reverse direction is transmitted from the terminal device. 16. The reverse direction in the code division multiple access system according to claim 15, further comprising a base station data transmission / reception step of receiving data transmitted through a common channel and receiving it through demodulation and channel decoding processes, etc. A common channel random connection method. The initial synchronization step includes
In the base station, an initial synchronization step of inputting a preamble transmitted from the terminal device via a reverse common channel and performing initial synchronization according to all useful preamble signatures;
In the base station, a data reception preparation step of notifying the base station data transmission / reception step of all the time delay characteristics corresponding to the acquisition preamble signature and preparing to receive data transmitted immediately;
The reverse connection common channel random connection method in the code division multiple access system according to claim 23, wherein the base station includes a step of notifying the acquisition preamble signature in the determination step. The determining step includes
In the base station, using the acquisition preamble signature input from the initial synchronization step, informing the data transmission / reception means of the corresponding code for spreading the band and preparing to receive the data to be transmitted immediately; ,
The reverse common channel in the code division multiple access system according to claim 23, further comprising: an output step in which the base station generates a signal only with an acquisition preamble signature and outputs the signal to the acquisition indication signal transmission step. Random connection method. In the acquisition indication signal transmission step, the base station sets a corresponding time in four signal systems, that is, a preamble signature, and transmits an acquisition signal only during a time corresponding to the acquisition preamble signature. The signal system and the corresponding time are set in the preamble signature, and the first anti-signal system that always transmits the signal regardless of the capture regardless of the capture, and the corresponding orthogonal code is transmitted in the preamble signature. A second on-off signal system for transmitting only symbols corresponding to the acquisition preamble signature, and assigning an orthogonal code to the preamble signature, setting the symbol for transmission, and setting the transmission symbol. Regardless of the symbol, it always applies to all preamble signatures. Is selected and transmitted to the acquisition display signal transmission system, and the first anti-signal system and the second anti-signal system use the captured preamble. The reverse common channel random in the code division multiple access system according to claim 23, wherein the acquisition display signal for the signature and the acquisition display signal for the preamble signature that has not been acquired are opposed to each other. Connection method. In the base station, the acquisition display signal transmission step includes a method of puncturing an existing forward common channel, a method of dedicating a separate channel having orthogonality to another forward common channel, and other forward common The random connection of the reverse common channel in the code division multiple access system according to claim 26, wherein the transmission is performed by selecting one of a method dedicated to a channel that does not have orthogonality to the channel. Method. In the base station,
A channel reservation request for requesting a general channel allocation to transmit large data;
Packet access to transmit short data,
Dividing the character of the data to be transmitted over the reverse common channel by RR to transmit intermediate size of data, which in properly assigned to the appropriate preamble signature, so that all terminals can recognize, forward random access method for reverse common channel in a code division multiple access scheme according to claim 15, wherein the transmitting via a directional common channel.   The code division multiple access according to claim 28, wherein in the packet access, a preamble signature assigned to packet access for transmitting short data is further subdivided and assigned according to a length of data transmission. Random connection method of reverse common channel in the system. For the channel reservation request,
Randomly select one of the preamble signatures assigned for channel reservation from the terminal device and transmit the preamble in the same manner as the packet access, and the base station performs initial synchronization using the preamble transmitted from the terminal device. To inform the acquisition preamble signature to all terminals via the forward common channel,
A terminal device that has transmitted an unacquired preamble signature randomly selects one of the preamble signatures allocated for channel reservation, determines a time slot for transmission, and retransmits the preamble.
The terminal device that has transmitted the acquisition preamble signature transmits data for channel reservation, and then transmits data for reservation to attempt channel reservation.
In the base station, after correctly receiving the data for channel reservation transmitted from the terminal device, inform the corresponding terminal of the channel reservation time and spreading code, transmission rate, etc. using the common channel,
The corresponding terminal transmits the data to be transmitted using the reserved time, spreading code, transmission rate, etc., performs closed loop power control using a power control command transmitted to the forward channel,
29. The reverse direction in the code division multiple access system according to claim 28, wherein when the final frame is transmitted, information indicating that the data transmission is completed is included in the data and transmitted to cancel the channel reservation. A common channel random connection method.   In order to change the channel reservation condition while using the reserved channel, the data for changing the channel reservation condition is transmitted simultaneously with the data transmission in the same manner as the operation for the packet access or the channel reservation request. The random connection method of a reverse common channel in the code division multiple access method according to claim 30. The terminal device receives the acquisition confirmation signal transmitted from the base station , and in the terminal device in which the preamble signature transmitted by itself is not acquired, the preamble signature and the slot are re-set at random, and only the amount already set The method of claim 15, further comprising a retransmission step of retransmitting the power-adjusted preamble.

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