JP4706745B2 - Wireless transmission method, wireless transmission system, wireless transmission device, and program - Google Patents

Description

  The present invention relates to a wireless transmission method, a wireless transmission system, a wireless transmission device, and a program.

  Conventionally, when performing wireless transmission of information, a method of defining a specific frame period in a wireless transmission path, packetizing the information, and transmitting the information wirelessly has been generally used. In recent years, methods for wirelessly transmitting various information such as wireless LAN, wireless ATM, and wireless IEEE1394 on the same wireless transmission path are being developed. For example, wireless IEEE1394 is a method of performing wireless transmission based on the IEEE1394 high-speed serial bus standard, and both transmission modes of isochronous transmission (at that time transmission) and asynchronous transmission (asynchronous transmission) are prepared.

  Furthermore, a method of transmitting information after securing a transmission band in advance for transmission of various information is also conceivable. For example, in wireless IEEE1394, for isochronous transmission, information transmission is performed after performing bandwidth reservation on a transmission path in a time-sharing manner.

  In the conventional wireless transmission methods, the structure of the transmission side device and the reception side device can be simplified by using the only modulation method and the only coding method.

  In addition, in the conventional wireless transmission method, in order to use the only modulation method and the only coding method, in the communication over a relatively short distance, the transmission output is suppressed and the transmission is performed, and the communication over a relatively long distance is performed. In general, communication is performed by increasing the transmission output.

  As in the conventional wireless transmission method, the method of changing the transmission output according to the communication distance is, for example, when transmitting a large amount of information, such as when transmitting moving image information, and transmitting according to the amount of information. There was a tendency for the error rate to increase.

  In addition, when transmission is performed using the only modulation method and the only coding method as in the conventional wireless transmission method, the amount of communication transmitted on the wireless transmission path, such as a mobile phone or digital broadcasting, is almost equal. If they are the same, efficient wireless transmission was possible.

  For example, when transmitting moving image information for recording a broadcast program for a long time and control code information for remote operation on the same wireless transmission path using a wireless home network, Regardless of the amount of information, the only modulation method and the only coding method were used.

  Furthermore, since the same modulation method and the same encoding method are used for both short-distance communication and long-distance communication, not only long-distance communication but also redundant error correction codes are added in short-distance communication. It was done.

  The present invention intends to propose a wireless transmission method that enables information transmission using the minimum necessary transmission band.

  In addition, the present invention intends to propose a wireless transmission method capable of selecting an optimal transmission format for bandwidth reservation transmission and performing information transmission.

  The present invention enables information transmission with good transmission path quality, and when information transmission transmission quality is good, by performing information transmission with a modulation scheme and encoding scheme faster than the standard transmission speed, A wireless transmission method that enables high-speed information transmission is proposed.

  The present invention seeks to propose a radio transmission apparatus that enables information transmission using a minimum necessary transmission band and enables information transmission between all communication stations in a predetermined radio network system. It is.

  The present invention provides a wireless transmission device capable of stably and continuously performing higher-quality information transmission by adding a reserved band as necessary when transmission quality is below a certain level. It is what we are going to propose.

  The present invention enables transmission of information using the minimum necessary transmission band, transmission system that enables reliable transmission using a wider band, and transmission system that enables high-speed transmission in a narrower band. Thus, the present invention intends to propose a radio transmission apparatus that can select an optimum scheme for information transmission each time by using a combination of a plurality of modulation schemes and a plurality of encoding schemes.

The wireless transmission method according to the present invention prepares a plurality of combinations of modulation schemes and coding rates of signals to be wirelessly transmitted within a predetermined wireless network system, and selectively uses an optimum combination among the plurality of combinations. Thus, information transmission is performed.

According to the present invention that written, an optimal combination from a plurality of combinations of modulation scheme and coding rate of the signal to be wirelessly transmitted selectively using, transmitting information.

Further, the present invention provides a communication station that reserves a transmission band, makes a transmission band reservation request to a control station that controls a radio network system, and selects a modulation scheme selected in a slot allocated by the control station, and This is a wireless transmission method in which information transmission is performed using a combination of encoding methods.

[Specific Examples of Embodiments of the Invention]
Below, the outline | summary of the radio transmission method and radio transmission apparatus of the specific example of embodiment of this invention is demonstrated. First, in order to perform wireless transmission, a plurality of signal formats of a modulation scheme and a coding scheme are prepared, and an optimum signal scheme is selected and transmitted each time.

  In addition, transmission control information is communicated between all communication stations by using the first modulation method and the first encoding method that are common on the wireless network, and information transmission between specific communication stations is performed. Is communicated using the second modulation scheme and the second encoding scheme.

  Here, the second modulation scheme and the second encoding scheme are a transmission method using a wider band and a method capable of transmission in a narrower band than the first modulation scheme and the first encoding scheme. It is assumed that a plurality of modulation schemes and encoding schemes can be used in combination.

  Further, when wirelessly transmitting an IEEE1394-compliant packet, for example, the first modulation method and the first encoding method are used for transmitting asynchronous information, and the second information is transmitted for isochronous information as necessary. Communication is performed using the modulation method and the second coding method.

  It is not always necessary to use the second modulation scheme and the second encoding scheme for transmission of isochronous information, and transmission may be performed using the first modulation scheme and the first encoding scheme. .

  Or, when applied to a method of reserving and transmitting a specific band on a wireless transmission path, band reservation is performed using the first modulation scheme and the first encoding scheme that are common on the wireless network. In the information transmission within the reserved band, communication is performed using the second modulation scheme and the second coding scheme in addition to the first modulation scheme and the first coding scheme.

  In addition, a transmission error rate or the like is measured during wireless transmission, and the modulation scheme and the coding scheme are switched as necessary from the information. For example, when a prescribed transmission error rate is exceeded, an additional reserved transmission band is secured, and the information transmission is continued by switching to a low-speed transmission method. If the transmission error rate is better than the specified transmission error rate, the transmission path utilization efficiency is improved by switching to a high-speed transmission method and transmitting information.

  Hereinafter, specific examples of embodiments of the present invention will be described in detail with reference to the drawings. First, a specific example of a wireless network system will be described with reference to FIG. In FIG. 1, WNT indicates a wireless network, which includes, for example, a wireless transmission device 104 as a control station and wireless transmission devices 101 to 103 as terminal communication stations. Each of the wireless transmission devices 101 to 104 includes a transmission / reception antenna.

  For example, a personal computer 11 and a printer output device 12 are connected to the wireless transmission device 101 via a cable L1.

  For example, a magnetic recording / reproducing device 13 is connected to the wireless transmission device 102 via a cable L2.

  For example, a set-top box 14 and a telephone device 15 are connected to the wireless transmission device 103 via a cable L3. The set-top box is used as a repeater for exchanging signals between a broadcasting station and a home, or a home adapter for controlling many programs by connecting a CATV line to a television receiver.

  For example, a television receiver 16 and a game machine 17 are connected to the wireless transmission device 104 via a cable L4.

  In the wireless network WNT, the wireless transmission device 104 as a control station can communicate with all the wireless transmission devices 101 to 103 as terminal communication stations. The communication station 101 cannot directly communicate with the distant communication station 103, but can directly communicate with the control station 104 and the communication station 102. When the communication station 101 communicates with the communication station 103, it may be performed via the control station 104. The communication station 102 can perform direct communication between the control station 104 and the communication stations 101 and 103. The communication station 103 cannot directly communicate with the distant communication station 101, but can communicate with the control station 104 and the communication station 102. The communication station 103 may communicate with the communication station 101 via the control station 104.

  FIG. 2 shows a configuration of a signal transmitted between communication stations (wireless transmission apparatuses 101 to 104) in a specific example network system. For example, data transmission is performed by defining a frame period. As a configuration. That is, as shown in FIG. 2, one frame period is defined by a predetermined period, a predetermined section at the head of the one frame period is set as a control information transmission area, and a downlink control area DC is included in the control information transmission area. An uplink control area UC is set.

  In the downlink control area DC, information related to the method of using the radio transmission path, such as the configuration status of the radio network and slot allocation information of the information transmission area in the radio network, is transmitted.

  In the uplink control area UC, all wireless transmission devices transmit and receive information in a time-sharing manner, so that the status of the devices constituting the network can be grasped from each other.

  Further, a section other than the control information transmission area of each frame is set as a media information transmission area MIT, and various data are transmitted by access control from the control station in the media information transmission area MIT.

  Further, as shown in FIG. 3, in the media information transmission area MIT, slots S1, S2, S3,..., S15, S16 are defined in a certain unit. For example, slots S1 to S13 are defined as isochronous. For wireless transmission, a configuration is adopted in which bandwidth reservation transmission is performed, for example, bandwidth reservations 1, 2, and 3, which are assigned to arbitrary information transmission by the control station. The management area is composed of the downlink control area UC and the uplink control area UC in FIG.

  Further, in this specific example, reservation is made in units of these slots, and information is transmitted so that information can be transmitted using an arbitrary modulation method or encoding method in the slot.

  That is, it is defined that any modulation scheme or coding scheme may be used between the transmitting station and the receiving station for the information transmission in the slot acquired for the arbitrary information transmission.

  The media information transmission area MIT has a configuration in which asynchronous (asynchronous) information is transmitted wirelessly in addition to isochronous transmission when slot allocation for bandwidth reservation transmission is not performed.

  In this specific example, information transmission common to these wireless networks can be performed using a specific modulation scheme or encoding scheme. For example, in order to reserve a slot for transmitting information, a configuration may be adopted in which a request is notified to the control station as asynchronous (asynchronous) information.

  FIG. 4 shows a configuration example of the wireless transmission devices 101 to 104 that constitute each communication station. Here, the wireless transmission apparatuses 101 to 104 are basically configured in common, and an antenna 21 that performs transmission and reception, and a wireless processing unit 22A that is connected to the antenna 21 and performs wireless transmission processing and wireless reception processing. , 22B and 22C are configured to be able to perform wireless transmission with other transmission apparatuses.

  In this case, as a transmission method in which transmission and reception are performed in the wireless processing units 22A to 22C, for example, a transmission method using a multicarrier signal called an OFDM (Orthogonal Frequency Division Multiplex) method is applied, As a frequency used for transmission and reception, for example, a very high frequency band (for example, 5 GHz band) is used.

  In this specific example, a relatively weak output is set for the transmission output. For example, when used indoors, the output is such that wireless transmission over a relatively short distance from several meters to several tens of meters is possible. It is as.

  The radio processing unit 22A is configured to perform modulation / demodulation processing based on the first modulation scheme and the first encoding scheme, and the radio processing unit 22B includes the second modulation scheme and the second modulation scheme. The radio processing unit 22C is configured to perform modulation / demodulation processing based on the third modulation scheme and the third encoding scheme. These are assumed to be selected and communicated in advance according to an instruction from the control unit 25.

  A data conversion unit 23 is provided that performs data conversion of signals received by the wireless processing units 22A to 22C and data conversion of signals transmitted from the wireless processing units 22A to 22C.

  The data converted by the data conversion unit 23 is supplied to the processing device connected via the interface unit 24, and the data supplied from the connected processing device is supplied via the interface unit 24 to the data conversion unit 23. It is the structure which can be supplied to and converted.

  Here, as an external interface of the interface 24 of the wireless transmission device, for example, audio and video information or various data information can be transmitted to and received from a device 28 connected via a high-speed serial bus 27 such as IEEE1394. The configuration is as follows. Alternatively, these wireless transmission devices may be built in the main body of the device 28 to be connected.

  Each unit in the wireless transmission device is configured to execute processing based on the control of the control unit 25 configured by a microcomputer or the like. In this case, when the signal received by the wireless processing units 22A to 22C is a control signal such as wireless transmission band reservation information, the received signal is supplied to the control unit 25 via the data conversion unit 23, The control unit 25 is configured to set each unit in the state indicated by the received control signal.

  Further, an internal memory 26 is connected to the control unit 25, and data required for communication control, reserved slot information, and information for designating a radio processing unit to be used for each information transmission are stored in the internal memory 26. Etc. are stored temporarily.

  When the received signal is a synchronization signal, the control unit 25 determines the reception timing of the synchronization signal, sets the frame period based on the synchronization signal, and executes the communication control process at the frame period. It is as composition to do.

  Also, control signals such as radio transmission band reservation information transmitted from the control unit 25 to other transmission devices are supplied from the control unit 25 to the radio transmission processing units 22A, 22B, and 22C via the data conversion unit 23. Then, it is designed to transmit wirelessly.

  FIG. 5 shows a transmission slot relationship between a combination of a plurality of modulation schemes and encoding schemes and a combination of modulation schemes and convolutional coding rates. Here, as a specific example, two modulation schemes and two convolutional coding rates are combined to prepare four rates, but it may be more or less than this rate set.

  First, as a combination of rate 1 used for basic transmission, for example, a combination using QPSK as a modulation scheme and applying a convolutional coding rate of R = 3/4 as a coding scheme is prepared.

  As a combination of rate 2 capable of high-speed transmission compared to rate 1, for example, a combination using 16QAM as a modulation method and applying a convolutional coding rate of R = 1/2 as a coding method is prepared. Yes.

  As a combination of rate 3 capable of low-speed transmission compared to rate 1, for example, a combination using QPSK as a modulation method and applying a convolutional coding rate of R = 1/2 as a coding method is prepared. Yes.

  In addition to these combinations, as a combination of rate 4 capable of ultra-high-speed transmission, for example, a combination using 16QAM as a modulation scheme and applying a convolutional coding rate of R = 3/4 as a coding scheme is prepared. ing.

  It shows how many slots on the wireless transmission path should be secured when transmission is performed using these transmission methods. That is, in the case of the normal transmission rate 1, 4 slots are required for transmitting the information amount of 4 slots.

  Here, when high-speed transmission rate 2 is applied, transmission is possible in 3 slots, and in low-speed transmission rate 3, 6 slots are required.

  Furthermore, it is shown that transmission can be performed with only two slots at the rate 4 of the ultrahigh-speed transmission.

  Note that these modulation schemes and encoding schemes are used for convenience to describe specific examples, and other combinations of modulation schemes and encoding schemes having similar functions may be used.

  FIG. 6 shows how much transmission band is required when acquiring a transmission slot on a wireless transmission path according to a combination of a plurality of modulation schemes shown in FIG. 5 and a convolutional coding rate. It shows what should be reserved.

  In FIG. 6, when the rate 1 used for normal transmission is applied, 4 slots are required, and when the rate 2 that is transmitted at a higher speed than the rate 1 is applied, only 3 slots are required. On the contrary, when rate 3 is transmitted at a lower speed than rate 1, 6 slots are required. Furthermore, if transmission at a higher speed than rate 2 is possible, this means that transmission can be performed while securing only 2 slots if ultra-high speed rate 4 can be applied.

  FIG. 7 illustrates an example of state transition of the transmission rate according to a specific example. Here, rate 1 which is a basic rate is set at the time of initial setting. For example, when the transmission error rate is equal to or higher than a certain level and the transmission quality is good, the rate is shifted to rate 2 which is a high-speed transmission rate. For example, when the transmission error rate falls below a certain level and the transmission quality deteriorates, the rate shifts to rate 3, which is a low-speed transmission rate.

  Similarly, even at the high-speed transmission rate 2, when the transmission quality is good, the rate shifts to the rate 4, which is a higher ultra-high-speed transmission rate, and when the transmission quality decreases, the rate is the normal transmission rate. Move to 1.

  At the low transmission rate 3, when the transmission quality is good, it shifts to the normal transmission rate, rate 1. However, when the transmission quality is lowered, there is no lower transmission rate. ) The transmission rate will be maintained. Alternatively, when transmission quality is deteriorated, a method of relay transmission via another station may be used as necessary.

  In the ultra-high-speed transmission rate 4, since there is no higher transmission rate, this transmission rate is maintained, and when the transmission quality is lowered, the transmission rate is shifted to a transmission rate 2 that is one step lower.

  FIG. 8 shows a procedure of a bandwidth reservation method and a bandwidth allocation method in bandwidth reservation transmission. Here, for convenience, a communication station that performs bandwidth reservation, a central control station that performs bandwidth allocation, and a transmission station or reception station that performs reservation transmission are represented as if they exist individually for each function, It is also possible to adopt a configuration having the functions of the communication station.

  First, a bandwidth reservation request is sent from the communication station that performs bandwidth reservation to the central control station. Next, when the transmission band can be allocated, a notification of band allocation is sent from the central control station to each station related to the transmission. Furthermore, for the confirmation, confirmation of bandwidth allocation is returned from each communication station to the central control station. Thereafter, the central control station simultaneously reports the start of bandwidth allocation transmission using the downlink control information. As a result, band reservation transmission using a normal band allocation transmission system is performed.

  The receiving station for reserved transmission is configured to report transmission quality in reserved transmission. In other words, if the transmission quality in the reserved transmission falls below a prescribed level and a transmission error may occur at the receiving station, the fact is reported to the transmitting station. For example, a configuration is assumed in which transmission quality is reported from a receiving station to a transmitting station using uplink control information.

  FIG. 9 shows a procedure for shifting to a low-speed transmission method by additionally reserving a transmission band when transmission quality deteriorates during band reservation transmission using the above-described method. First, when the transmission quality of the reserved transmission decreases, the receiving station that performs the reserved transmission reports the transmission quality deterioration to the transmitting station. The transmitting station that has received the transmission quality degradation report notifies the central control station of a bandwidth reservation addition request as necessary.

  Here, an example of immediately reporting to the central control station has been shown, but if necessary, for example, when a report of transmission quality degradation is received over a plurality of transmission frames, a bandwidth reservation addition request is centrally controlled. You may take the structure notified to a station.

  Upon receiving this bandwidth reservation addition request, the central control station broadcasts additional allocation of bandwidth allocation transmission using downlink control information if additional allocation is possible for the corresponding bandwidth reservation transmission. Send.

  In addition, when performing additional allocation, the central control station broadcasts the timing for shifting to the low-speed transmission method at the same time as transmission and reception after a certain period of time in order to synchronize the transmission side and the reception side. If the transition timing is not reached, communication using the conventional normal transmission method is continued. Then, a control method may be adopted in which a transmission side and a reception side simultaneously shift to a low-speed transmission method after a frame whose bandwidth allocation is changed arrives.

  In FIG. 10, when bandwidth reservation transmission is performed using the normal transmission method, a transmission quality sufficient for information transmission is ensured, and a high-speed transmission method using only a part of the reserved bandwidth can be used. If there is, a procedure for releasing a part of the reserved transmission band is shown as necessary.

  In this case, in the reserved transmission transmitting station, the transmission quality information sent from the reserved transmission receiving station is temporarily used to determine whether it can be applied to the high-speed transmission method of the reserved transmission. A specific example is shown in which transmission is performed and release of the reserved bandwidth is sent to the central control station if high-speed transmission satisfies the transmission quality.

  First, when the transmission quality information sent from the receiving station for reserved transmission is good, a notice of temporary high-speed transmission is notified to the receiving station. This notification describes, for example, that high-speed transmission is temporarily performed in a specified frame. Further, for this confirmation, the receiving station returns confirmation of this temporary high-speed transmission notice. Here, an example of reporting to the central control station immediately has been shown, but if necessary, for example, when a report indicating that the transmission quality is good over a plurality of transmission frames is received, a temporary high-speed A configuration for notifying the transmission station of the transmission advance notice may be adopted.

  Then, when the designated frame arrives, information transmission by the temporary high-speed transmission method is simultaneously performed between the transmitting station and the receiving station. The result of this temporary high-speed information transmission is reported using a transmission quality confirmation notification from the receiving side to the transmitting side. Here, when it is determined that sufficient transmission quality can be ensured with only the high-speed transmission band, a reservation band reduction request is sent from the transmitting station to the central control station or the receiving station. The central control station that has received this reserved bandwidth reduction request uses downlink control information to broadcast the implementation of bandwidth reduction. At this time, the control station also notifies the timing at which the reserved bandwidth is reduced after the designated frame. Here, a specific example in which high-speed transmission is continued thereafter is shown. However, even if temporary high-speed transmission is performed once and then the transmission is shifted to high-speed transmission, sufficient transmission quality is ensured. If it is determined that the transmission can be performed, a method of switching to high-speed transmission again may be taken. Then, a control method may be used in which a part of the reserved bandwidth is released after a frame whose bandwidth allocation is changed arrives.

  FIG. 11 shows an operation flow of a band reservation method (transmission band acquisition request procedure) of a specific example. First, when performing isochronous transmission, it is assumed that the wireless transmission device serving as a bandwidth reservation station receives the bandwidth reservation transmission request shown in step ST-1. In this case, in step ST-2, information on the connection relationship between the transmitting station and the receiving station performing isochronous transmission is acquired. It is assumed that this includes information on the connection status of both sides.

  Further, in step ST-3, it is determined from the connection state between these two stations whether or not transmission at a rate lower than the standard transmission rate is necessary. That is, for example, since the transmission error rate is higher than a predetermined value, it is determined whether or not transmission using a modulation method or coding method with higher redundancy is necessary.

  If it is determined that low-speed transmission is necessary, the number of slots required for low-speed transmission is calculated in step ST-4, and whether a corresponding empty slot exists on the wireless transmission path in step ST-5. Judge whether or not.

  If there is an empty slot, a transmission slot new request is transmitted to the control station in step ST-10. If there is no empty slot, the process proceeds to step ST-7 to calculate the number of slots necessary for normal transmission.

  If low-speed transmission is not necessary from the branch of step ST-3, it is determined in step ST-6 whether high-speed transmission is possible. That is, for example, since the transmission error rate is lower than a predetermined value, it is determined whether transmission using a modulation method or coding method with lower redundancy is possible.

  If it is determined that high-speed transmission is impossible, the process proceeds from step NO to step ST-7 to calculate the number of slots required for normal transmission. It is determined whether or not there is a corresponding empty slot.

  If high-speed transmission is possible at the branch of step ST-6, the number of slots required for high-speed transmission is calculated in step ST-8, and the empty slot corresponding to the wireless transmission path is calculated in step ST-9. It is determined whether or not exists.

  If it is determined in step ST-9 that there is an empty slot, a transmission slot new request is transmitted to the control station of the network in step ST-10. If there is no empty slot, the reservation process is exited, and notification that bandwidth reservation transmission is impossible is made in step ST-13.

  After transmitting a transmission slot new request to the network control station in step ST-10, whether or not a transmission slot assignment has been received from the network control station in step ST-11 until a predetermined time has elapsed. Make a decision. If assigned, transmission is performed using the assigned slot and the process is terminated. If no assignment is received, the number of retransmissions of the transmission slot new request is confirmed in step ST-12.

  If the number of retransmissions does not exceed the prescribed number, the process proceeds to step ST-10, and a new transmission slot request is transmitted again to the network control station. If the number of retransmissions exceeds the specified number, the reservation process is exited, and notification that bandwidth reservation transmission is impossible is made at step ST-13.

  FIG. 12 shows a transmission band allocation procedure by the control station. First, in step ST-1, the control station receives a transmission slot request from a communication station constituting the wireless network. Based on the information, it is determined in step ST-2 whether slot allocation is possible.

  If slot allocation is possible, the process proceeds to step ST-3, and the transmission slot is registered for information transmission of the corresponding communication station. Here, in step ST-4, it is determined whether or not the slot assignment is a new slot assignment.

  If it is a new slot assignment, the process proceeds to step ST-5, where a bandwidth reservation number is issued and registered. This bandwidth reservation number is assigned for use in identifying subsequent increase / decrease in slot allocation. In step ST-6, the slot allocation information is sent to the requesting station, transmitting station, and receiving station.

  Thereafter, in step ST-7, when an allocation confirmation is received from each communication station within a predetermined time, the reservation allocation of the corresponding slot is completed. When the reservation allocation is completed, in step ST-9, it is reported to the entire network that the reservation allocation of the corresponding slot has been performed in the downlink management information.

  If it is determined in step ST-4 that the slot assignment is not a new slot assignment, the process proceeds from step NO to step ST-8, where the transmission side and the reception side are synchronized to update the slot assignment. Set the timing. Thereafter, in step ST-9, in the downlink management information, the reservation allocation change of the corresponding slot and the update timing are reported to the entire network.

  In step ST-7, if the allocation confirmation cannot be received from each communication station within a predetermined time, the designated number of retransmissions is determined in step ST-10 from the NO branch. If the number of retransmissions has not been reached, the process proceeds to step ST-6 to retransmit the slot allocation information. If the number of retransmissions has been exceeded, in step ST-11, the bandwidth reservation number set in step ST-5 is deleted, and in step ST-12, an allocation impossible notification is sent to the slot allocation requesting station, transmitting station, and Send to the receiving station.

  In addition, if it is determined in step ST-2 that slot allocation is impossible, an allocation impossible notification is sent to the slot allocation requesting station in step ST-12.

  FIG. 13 shows a procedure for returning the slot assignment confirmation. Here, in step ST-1, the slot assignment sent from the control station is received by the reservation station, the transmission station, or the reception station, and it is known that the corresponding slot is reserved for the band together with the band reservation number.

  In step ST-2, a slot allocation confirmation is returned to the control station. Each communication station can actually start transmission from slot assignment information of downlink control information sent from the control station thereafter.

  FIG. 14 shows a monitoring procedure on the receiving station side of slot assignment transmission. Here, a configuration is considered in which, during slot transmission reception, for example, the transmission quality in the reception state of the slot is reported to the transmission station or the control station using an uplink control area.

  First, in step ST-1, it is determined whether or not slot allocation is being received. If the slot is being received, the transmission error rate in the corresponding reception slot is determined in step ST-2. For the determination of the transmission error rate, for example, the transmission error rate without error correction may be used as a determination material. In addition, this determination may reflect the result of a long-term transmission error rate over a plurality of frames.

  If the transmission error rate in the transmission slot is equal to or lower than a predetermined level, it is determined in step ST-3 that the transmission quality is deteriorated, and then a transmission quality confirmation notification is reported in step ST-4. . As this transmission quality confirmation notification reporting method, for example, a configuration for reporting for each frame using an uplink control area will be described with reference to FIG. In addition, if the same function is performed, a transmission quality confirmation notification report may be made using another method.

  FIG. 15 shows a processing procedure at the receiving station during slot assignment transmission. First, in step ST-1, it is determined whether or not slot assignment transmission is being received. If slot assignment transmission is being received, it is determined in step ST-2 whether or not a temporary high-speed transmission notice has been received. If a temporary high-speed transmission notice is received, it is determined in step ST-3 whether high-speed transmission can be received. If high-speed transmission is possible, in step ST-4, the high-speed transmission information described in the temporary high-speed transmission notice and the setting of the frame for temporary high-speed transmission are acquired, and high-speed transmission is performed based on the information. Set the frame to be used. Thereafter, in step ST-5, a temporary high-speed transmission confirmation is returned to the transmitting station. In step ST-3, if high-speed transmission is impossible, the process is exited.

  If a temporary high-speed transmission notice has not been received in step ST-2, it is determined in step ST-6 whether or not it is a frame for high-speed transmission. In step ST-7, the demodulator is set based on the high-speed transmission method and information is received. If it is not a frame for high-speed transmission, it is further determined in step ST-8 whether or not it is a frame for low-speed transmission. If it is a frame for low-speed transmission, it is determined in step ST-9. The demodulator is set based on the low-speed transmission method to receive information. In other cases, in step ST-10, a demodulator is set based on a normal transmission method, and information is received. After receiving them, in step ST-11, a transmission quality confirmation notification is reported using the sequence shown in FIG.

  FIG. 16 shows a monitoring procedure on the transmission station side of slot assignment transmission. First, in step ST-1, it is determined whether or not slot assignment transmission is being transmitted. If the slot allocation transmission is being transmitted, a transmission quality confirmation notification is received from the slot allocation receiving station in step ST-2.

  Further, in step ST-3, it is determined whether or not the transmission quality is currently confirmed immediately after the temporary high-speed transmission. Here, if the normal transmission quality is confirmed, it is determined whether or not the transmission quality in the corresponding slot is deteriorated in step ST-4 from the NO branch. If a decrease in transmission quality is recognized, it is determined in step ST-5 whether information transmission at low speed is possible. For example, when there is no lower transmission rate than this, it is unavoidable that the processing is skipped in order to continue transmission at the current transmission rate. If low-speed transmission is possible, the number of transmission slots required for low-speed transmission is calculated in step ST-6.

  Further, in step ST-7, it is determined whether or not there is an empty slot corresponding to the number of corresponding slots on the wireless transmission path. If there is an empty slot, a transmission slot additional allocation request is transmitted to the control station in step ST-8. If there is no empty slot, the processing is terminated as it is in order to continue the current transmission.

  If it is determined in step ST-4 that no deterioration in transmission quality is observed, it is determined in step ST-9 whether the quality is continuously good. If the transmission quality is continuously good, it is determined in step ST-10 whether or not high-speed information transmission is possible. If there is no higher transmission rate than this, the process is exited.

  If high-speed transmission is possible, a notification of temporary high-speed transmission notice is transmitted to the receiving station in step ST-11. The temporary high-speed transmission notice includes information on high-speed transmission speed and information on a frame for performing temporary high-speed transmission.

  If it is determined in step ST-3 that the transmission quality is confirmed immediately after the temporary high-speed transmission, the process proceeds to step ST-12 to check whether the transmission quality in the high-speed transmission is good. If the transmission quality is good, a transmission slot reduction request is transmitted to the control station in step ST-13. If the transmission quality is not good, transmission at the normal transmission rate is continued from the NO branch.

  FIG. 17 shows a processing procedure at the transmitting station during slot assignment transmission. First, in step ST-1, it is determined whether or not slot assignment transmission is being transmitted. When the slot allocation transmission is being transmitted, at step ST-2, when the temporary high-speed transmission confirmation sent from the receiving station side is received, at step ST-3, the specified frame is transmitted. Make settings for temporarily performing high-speed transmission using the specified slot.

  If a temporary high-speed transmission confirmation is not received in step ST-2, it is determined in step ST-4 whether or not the frame is a frame for high-speed transmission. In step ST-5, the modulation device is set based on the high-speed transmission method, and information is transmitted.

  If it is not a frame for high-speed transmission, it is further determined in step ST-6 whether it is a frame for low-speed transmission. If it is a frame for low-speed transmission, it is determined in step ST-7. Information is transmitted by setting the modulation device based on the low-speed transmission method. In other cases, in step ST-8, the modulation apparatus is set based on the normal transmission method, and information is transmitted.

  FIG. 18A shows a configuration example of downlink control packet information sent from the control station configuring the network to each communication station in the downlink control area. In the figure, a packet ID indicating the type of packet, a network ID for identifying this wireless network, reserved slot information indicating the state of a reserved transmission slot, a bandwidth allocation update timing describing information on a frame for performing bandwidth allocation update, A network station link map (Network Station Link Map) or the like representing the state of communication stations in the network is constructed, and CRC (Cyclic Redundancy Check) information is attached and transmitted.

  FIG. 18B shows a configuration example of uplink control packet information sent from each communication station configuring the network in the uplink control region. In the figure, packet ID indicating the type of packet, slot transmission quality confirmation information for confirming communication quality during slot transmission, station link map (Station Link Map) indicating the status of communication stations that can communicate with its own station, temporary High-speed transmission notification information, transmission rate information indicating a transmission rate, and the like, which are used when performing general high-speed transmission, CRC information is attached to the transmission information.

  FIG. 18C shows a configuration example of transmission slot request packet information sent from a communication station that performs band reservation to a control station that forms a network when band reservation transmission is performed. In the figure, a packet ID indicating the type of packet, a command (Command) of this packet, a destination communication station ID for identifying the destination communication station of this packet, a source communication station ID for identifying the source communication station of this packet, and a bandwidth It consists of a bandwidth reservation number used for adding and deleting reservations (not used for new requests), information on the number of requested slots for requesting bandwidth allocation, transmission rate information as the transmission rate, etc., with CRC information attached Is transmitted.

  FIG. 18D shows a configuration example of a transmission slot allocation packet sent from a control station that constitutes a network to each communication station that performs band reservation transmission when band reservation transmission is performed. In the figure, a packet ID indicating the type of packet, a command of this packet, a destination communication station ID for identifying the destination communication station of this packet, a source communication station ID for identifying the source communication station of this packet, and this new bandwidth reservation Is composed of a bandwidth reservation number assigned to the device, assignment reservation slot information indicating the assigned transmission band, transmission rate information as the transmission rate, and the like, and CRC information is attached to the transmission.

According to the present invention, in a predetermined wireless network system, a plurality of combinations of modulation schemes and coding rates of signals to be transmitted wirelessly are prepared, and an optimal combination is selectively used from among the plurality of combinations. Since information transmission is performed, it is possible to obtain a wireless transmission method that enables information transmission using a minimum necessary transmission band.

It is a block diagram which shows the radio | wireless network system of the specific example of embodiment of this invention. It is a diagram which shows the radio | wireless transmission frame of a specific example. It is a diagram which shows the example of the band reservation in the band reservation transmission of a specific example. It is a block diagram which shows the structure of each radio | wireless transmission apparatus in the radio | wireless network system of the specific example of FIG. It is a diagram which shows the relationship between the combination of the modulation system of a specific example, a convolutional coding rate, and a transmission slot. It is a diagram which shows the band reservation example in each transmission rate of a specific example. It is a diagram which shows the example of the state transition of the transmission rate of a specific example. It is a diagram which shows the procedure of the band reservation method and the band allocation method in the band reservation transmission of a specific example. It is a diagram which shows the procedure which transfers to a low-speed transmission system by additionally reserving a transmission band when transmission quality falls during the band reservation transmission of a specific example. It is a diagram which shows the band partial release procedure by the high-speed transmission transition of a specific example. It is a flowchart which shows the acquisition request | requirement procedure of the transmission band of a specific example. It is a flowchart which shows the transmission band allocation procedure by the control station of a specific example. It is a flowchart which shows the slot allocation confirmation procedure of a specific example. It is a flowchart which shows the monitoring procedure in the receiving station of a specific example. It is a flowchart which shows the process sequence in the receiving station in slot allocation transmission of a specific example. It is a flowchart which shows the monitoring procedure in the transmission station of the slot allocation transmission of a specific example. It is a flowchart which shows the process sequence in the transmitting station in slot allocation transmission of a specific example. A is a diagram showing a configuration example of downlink control packet information. B is a diagram showing a configuration example of uplink control packet information. FIG. It is a diagram which shows the structural example of C transmission slot request packet. D is a diagram showing a configuration example of a transmission slot allocation packet. FIG.

Explanation of symbols

  WNT wireless network, 101-104 wireless transmission device, L1-L4 cable, 11 personal computer, 12 printer output device, 13 magnetic recording / playback device, 14 set-top box, 15 telephone device, 16 television receiver, 17 game device, 21 transmitting / receiving antenna, 22A to 22C wireless processing unit, 23 data conversion unit, 24 interface, 25 control unit, 26 internal memory, 27 serial bus, 28 connected device

Claims (7)

Within a given wireless network system, by setting the frame period in a predetermined cycle, the radio transmission method Ru set Teisu the transmission band of the frame period into a predetermined slot unit,
Prepare multiple combinations of modulation and coding schemes for signals transmitted wirelessly,
Based on the combination of the selected modulation method and coding method, the number of slots suitable for selectively using the optimum combination among the plurality of combinations according to the state of communication quality of the transmission path during data transmission Calculated,
The communication station that reserves the transmission band makes a reservation request for the transmission band to the control station that controls the radio network system, and in the slot allocated by the control station, the selected modulation scheme and A wireless transmission method for transmitting information using a combination of encoding methods. The transmission band reservation request is transmitted using an asynchronous transmission area, and the slot allocation is notified in downlink management information sent from the control station.
The wireless transmission method according to claim 1. Within a given wireless network system, by setting the frame period in a predetermined cycle, the set Teisu Ru wireless transmission system in a predetermined slot unit transmission band of the frame period,
Means for preparing a plurality of combinations of modulation schemes and encoding schemes for signals transmitted wirelessly;
Based on the combination of the selected modulation method and coding method, the number of slots suitable for selectively using the optimum combination among the plurality of combinations according to the state of communication quality of the transmission path during data transmission Means for calculating
The communication station that reserves the transmission band makes a reservation request for the transmission band to the control station that controls the radio network system, and the selected modulation scheme and A wireless transmission system comprising means for transmitting information using a combination of encoding methods . The transmission band reservation request is transmitted using an asynchronous transmission area, and the slot allocation is notified in downlink management information sent from the control station.
The wireless transmission system according to claim 3. Within a given wireless network system, by setting the frame period in a predetermined cycle, the radio transmission device Ru set Teisu the transmission band of the frame period into a predetermined slot unit,
Means for preparing a plurality of combinations of modulation schemes and encoding schemes for signals transmitted wirelessly;
Based on the combination of the selected modulation method and coding method, the number of slots suitable for selectively using the optimum combination among the plurality of combinations according to the state of communication quality of the transmission path during data transmission Means for calculating
A request for reservation of the transmission band is made to a control station that controls the wireless network system, and information transmission is performed using a combination of the selected modulation method and coding method in a slot allocated by the control station. And a wireless transmission device. The transmission band reservation request is transmitted using an asynchronous transmission area, and the slot allocation is notified in downlink management information sent from the control station.
The wireless transmission device according to claim 5. Within a given wireless network system, by setting the frame period in a predetermined cycle, the radio transmission method Ru set Teisu a predetermined slot unit transmission band of the frame period, the modulation scheme and coding of the signals transmitted wirelessly A step of preparing a plurality of combinations of the conversion methods;
Based on the combination of the selected modulation method and coding method, the number of slots suitable for selectively using the optimum combination among the plurality of combinations according to the state of communication quality of the transmission path during data transmission Calculating step,
A request for reservation of the transmission band is made to a control station that controls the wireless network system, and information transmission is performed using a combination of the selected modulation method and coding method in a slot allocated by the control station. A program that causes a computer to realize the steps to be performed.

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