JPH07118693B2 - Wireless communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A wireless communication system capable of performing bidirectional communication using a single frequency by compressing information into bursts and alternately transmitting and receiving the information between opposite devices. suggest.

Furthermore, we propose a method of synchronizing the transmission and reception signals of the master and slave stations.

[Industrial application field]

The present invention relates to a wireless communication system, and more particularly to a wireless communication system in which the configuration of a wireless device is simplified by introducing a time division direction control transmission (ping-pong transmission) system in a wireless transmission path.

[Prior Art] FIG. 9 shows a schematic configuration of a conventional two-way wireless communication system, in which two wireless devices facing each other, for example, a wireless base station A and a wireless device B, are connected in a downward direction. It is shown that communication is performed using the frequency f ₁ and the frequency f ₂ in the upstream direction.

When bidirectional communication is performed in the wireless communication system as described above, it has been necessary in the conventional method to allocate two frequencies to the upstream transmission path and the downstream transmission path.

FIG. 10 shows an example of the configuration of a transmitter / receiver section of a radio device in the conventional system, which includes a transmission frequency conversion section 1 for converting the frequency of a modulation signal from a modulator (not shown), and a high output amplifier (HPA) 2. From a transmission unit that generates a transmission signal with a fair frequency f ₁ , a low noise amplifier (LNA) 3 that amplifies a reception signal with a frequency f ₂ , and a reception frequency conversion unit 4 that converts the reception signal into an intermediate frequency (IF) Each of the receiving unit that receives a signal of a flat frequency f ₂ , the transmitting / receiving demultiplexer 6 that separates the transmitting signal and the receiving signal by interposing between the antenna 5 and the transmitting unit and the receiving unit, and the transmitting unit and the receiving unit, respectively. And a local oscillator 7 for supplying a local frequency signal to the frequency converters 1 and 4. If a synthesizer is used for the local oscillator 7, a multi-channel switchable radio device is constructed. The transmission / reception duplexer 6 includes a transmission band filter 6A that selectively passes a signal of the transmission frequency f ₁ , a reception band filter 6B that selectively passes a signal of the reception frequency f ₂ , and an antenna from the transmission band filter 6A. 5 and antenna 5
An antenna sharing device (H) 6C coupled to the reception band filter 6B is provided.

2. Description of the Related Art A conventional wireless device that performs bidirectional communication requires a duplexer including a transmission band filter and a reception band filter in order to separate a transmission frequency signal and a reception frequency signal. Further, since signals of different frequencies are used for transmission and reception to operate simultaneously, it is necessary to sufficiently perform electromagnetic shielding between the transmission unit and the reception unit.

In this case, since the duplexer is composed of a passive circuit network, it is difficult to reduce the size and the size of the IC, and the electromagnetic shield has a problem that it hinders the reduction in size and weight of the device.

[Problems to be Solved by the Invention]

Since the object of the present invention is to alternately transmit and receive bursts between opposed devices and perform bidirectional communication using a single frequency, a transmission / reception duplexer is not required and an electromagnetic shield is not required. Is to provide a wireless communication system that can be made smaller and lighter.

[Means for Solving the Problems]

 The present invention has the principle configuration shown in FIG.

As shown in FIG. 1 (a), a first aspect of the present invention includes a transmitting means 101 and a receiving means 102 in both devices in a wireless communication system for performing communication between both devices using a single frequency. , Two-way communication is performed by alternately transmitting and receiving bursts between the two devices.

The transmission means 101 is for converting the speed of digitalized transmission information, bursting it, and transmitting it.

The receiving means 102 performs speed conversion of the received bursted information and reproduces digitized transmission information.

The second invention is, as shown in FIG. 1 (b), transmitting means 101 for speed-converting digitized transmission information and bursting it and sending it, and speed-converting the received bursted information for digitalization. In a wireless communication system in which both opposing devices are provided with receiving means 102 for reproducing the converted transmission information, and a bidirectional communication is performed between the opposing devices by alternately transmitting and receiving bursts using a single frequency, a clock The playback means 103 is provided in both devices, and the one of the two devices that makes the call first becomes the master station, the master station transmits and receives in synchronization with the clock of its own station, and the slave station clocks reproduced from the burst of the master station. It is designed to transmit and receive in synchronization with.

The clock reproducing means 103 reproduces a clock from the received burst.

A third invention is, as shown in FIG. 1 (c), transmitting means 101 for speed-converting digitized transmission information and bursting it, and speed-converting the received bursted information for digitalization. Receiving means 102 for reproducing the converted transmission information is provided in both opposing devices, and bursts are alternately transmitted and received using a single frequency to perform bidirectional communication between the opposing devices, and a clock is used from the received burst. Both devices are provided with a clock reproduction means 103 for reproducing the clock, and the one that has called first becomes the master station, the master station transmits and receives in synchronization with the clock of its own station, and the slave station bursts the master station. In the wireless communication system for transmitting and receiving in synchronization with the clock reproduced from, the unique word sending means 104,
The delay time measuring means 105 is provided, the slave station immediately returns the burst of its own station when it receives the burst of the master station, and the master station is provided with a guard bit of a length corresponding to the calculated delay time. The transmission burst is transmitted.

The unique word sending means 104 sends a unique word in a transmission burst.

The delay time measuring means 105 compares the unique word in the reception burst with the unique word sent by the local station to obtain the delay time between both devices.

Therefore, the structure of the present invention is as follows. That is,
In a wireless communication system in which bi-directional communication is performed between two opposing devices, a first device burst-outputs and modulates digitized transmission information at a first timing that is repeatedly generated by speed conversion, and modulates the transmission information. Further, a first transmitting means (101) for performing frequency conversion into a predetermined frequency and transmitting the second frequency, and a second repetitive generation which is different from the first timing.
First receiving means (102) for frequency-modulating, demodulating, and speed-converting the burst information of a predetermined frequency received at the timing
And a switching means connected to an antenna, the antenna being connected to the first transmitting means (101) side at a first timing and being connected to the first receiving means (102) side at a second timing ( 8 and 9), the second device opposite to the device converts the digitized transmission information into a burst at the second timing, outputs it, modulates it, and further converts it into a predetermined frequency. Second transmitting means for transmitting (10
1) and second receiving means (102) for frequency-converting, demodulating, and speed-converting the burst information of a predetermined frequency received at the first timing to reproduce digitized transmission information. A switching means (8) connected to the antenna, the antenna being connected to the second transmitting means (101) side at a second timing and being connected to the second receiving means (102) side at a first timing. , 9), and two-way communication is performed by alternately transmitting and receiving the bursted information in a time division manner between both devices using a common frequency for transmission and reception, as a wireless communication system. Have.

Alternatively, both devices are provided with a clock regenerating means (103) for regenerating a clock from a received burst, and the one of the two devices that has made a call first becomes the master station, and the master station transmits and receives in synchronization with its own clock. At the same time, the slave station has a configuration as a wireless communication system characterized by transmitting and receiving in synchronization with a clock reproduced from the burst of the master station.

Alternatively, a delay time for calculating a delay time between both devices by comparing the unique word sending means (104) for sending a unique word in the transmission burst with the unique word in the reception burst and the unique word sent by the own station. A measuring means (105) is provided so that the slave station immediately returns the burst of its own station when it receives the burst of the master station, and the master station provides a guard bit of a length corresponding to the delay time obtained. It is configured as a wireless communication system characterized in that the transmission burst is transmitted.

Alternatively, in a wireless communication system of a device that performs bidirectional communication with an opposite device, a first transmission speed conversion is performed on digitized transmission information, and a burst signal is output at a first timing that is repeatedly generated.
Speed converting means (13), modulating means for modulating the burst signal, transmitting means (101) for frequency-converting the modulated signal into a signal of a predetermined frequency by a local oscillation frequency, and transmitting the signal. Unlike the timing of, the second that occurs repeatedly
A receiving means (102) for receiving a signal of a predetermined frequency in a burst at a timing of, and converting the frequency by the local oscillation frequency, a demodulation means for demodulating the frequency-converted signal, and a speed conversion of the demodulated signal. Second speed conversion means (1
4) and control so that the signal from the transmission means (101) is output through the antenna at the first timing so that the signal is received by the reception means (102) through the antenna at the second timing. And a control means for performing the bidirectional communication with the opposite device by alternately transmitting and receiving the bursted information in a time division manner using a common frequency for transmission and reception.

[Action]

Between the two devices facing each other, the transmission side performs speed conversion of the digitized transmission information into bursts and sends out at the first frequency, and the reception side transmits the received bursted information of the first frequency at the speed. Realizes a wireless communication system in which two-way communication is performed by alternately transmitting and receiving bursted information using a single frequency between both devices by reproducing converted and digitized transmission information. be able to. At this time, in both devices, it is possible to regenerate the clock from the reception burst, and the one that has called out first becomes the master station, and the master station transmits and receives in synchronization with the clock of its own station. By transmitting and receiving in synchronization with the clock reproduced from the burst of the master station, the slave station can synchronize the transmission and reception signals in both devices. Although this system has a simple device configuration, the distance between the master station and the slave station is limited to within the propagation delay time corresponding to 1 bit, and the service area is limited to a relatively narrow range.

In addition, both devices should be able to send a unique word in the transmission burst, and compare the unique word in the reception burst with the unique word sent by the local station to determine the delay time between the local device and the partner device. The slave station returns the burst of its own station as soon as it receives the burst of the master station, and the master station provides a guard bit of a length corresponding to the calculated delay time. By transmitting the transmission burst, it is possible to realize a wireless communication system without the limitation of the service area.

〔Example〕

FIG. 2 illustrates the outline of the wireless communication system of the present invention, and illustrates the wireless time-division directional control transmission system. In FIG. 2, the communication between the wireless base station A and the wireless device B is sequentially burst-like, such as A → B, B → A, A → B, ... Has been shown to configure a time division directional control transmission scheme.

FIG. 3 shows a wireless communication system as an embodiment of the present invention, and shows an example of the configuration of a transmission / reception unit in a wireless device of the present invention. It is illustrated. In the figure, the same parts as those in FIG. 10 are indicated by the same numbers, and 8 and 9 are transmission / reception changeover switches, which are constituted by pin diodes or the like. Again 10
Is a bandpass filter.

During transmission, the transmission / reception switching switch 8 is turned on based on a transmission / reception control signal from a transmission / reception control unit (not shown), and the transmission / reception switching switch 9 is a high output amplifier (HP
A) It has been switched to the 2 side. A modulation signal from a modulator (not shown) is mixed with a signal of the local oscillation frequency of the local oscillator 7 in the transmission frequency conversion unit 1 to be frequency-converted to generate a signal of the transmission frequency, the output of which is high output through the transmission / reception switch 8. The output of the high-power amplifier (HPA) 2 is added to the amplifier (HPA) 2 and amplified, and then the output of the high-output amplifier (HPA) 2 is applied to the bandpass filter 10 via the transmission / reception changeover switch 9. The band filter 10 has a transmission / reception frequency f as a pass band, and the output of the high power amplifier (HPA) 2 is applied to the antenna 5 via the band filter 10 and sent to the other side.

During reception, the transmission / reception selector switch 8 is turned off, and the transmission / reception selector switch 9 is set to the low noise amplifier (LNA) 3
Has been switched to. The signal input from the antenna 5 is added to the low noise amplifier (LNA) 3 via the bandpass filter 10 and the transmission / reception changeover switch 9 and amplified, and the output is a signal of the local oscillation frequency of the local oscillator 7 in the reception frequency conversion unit 4. Is mixed and frequency-converted to generate an intermediate frequency signal, which is added to a demodulator (not shown) and demodulated.

FIG. 4 shows a configuration example of an audio signal processing unit system corresponding to the transmitting / receiving unit shown in FIG. 3, in which (a) is a transmitting side audio processing unit for generating an input signal to the modulator. The voice signal from the microphone 11 is encoded through the voice coder 12 and converted into a digital signal, and further converted into a double speed in the speed conversion unit 13 to generate a modulator input signal. (B) shows a voice processing unit on the receiving side for converting the output of the demodulator into a voice signal. The demodulated signal is converted into a speed of 1/2 in the speed conversion unit 14 and decoded in the voice decoder 15 to convert the voice signal. It is reproduced and sent out as sound from the speaker 16.

FIG. 5 is a time chart showing transmission / reception signals in the audio signal processing system shown in FIG. 4, in which (a) shows the output of the voice coder 12 and the audio signal is encoded at 16 kbps. (B) shows the output of the speed conversion unit 13 on the transmission side,
The output of the voice coder 12 is speed-converted to 32 kbps every burst cycle. (C) shows the input of the speed conversion unit 14 on the receiving side, which consists of a 32 kbps burst. (D) shows the input of the voice decoder 15, and the speed is converted to 16 kbps.

In FIG. 5, a transmission / reception control not shown so that the signal after speed conversion on the transmitting side shown in (b) and the signal before speed conversion on the receiving side shown in (c) are alternately generated in each burst cycle. Controlled by the department. This signal corresponds to the signal transmitted in a time-divisionally controlled manner between the two devices shown in FIG.

As described above, in the wireless communication system shown in FIGS. 2 to 5, at the time of transmission, the transmission signal is digitized to double the data rate and transmitted, for example, as an upstream burst, and the reverse operation is performed at the time of reception. Go and receive the input signal.

Therefore, in the wireless communication system of the present invention, since the wireless unit transmits and receives at a single frequency, there is no need to use a duplexer as in the conventional system, and instead, a transmission / reception changeover switch using a pin diode or the like, It suffices to switch between transmission and reception. In the embodiment of FIG. 3, the transmission / reception changeover switch 8 is also provided in the preceding stage of the high-power amplifier (HPA) 2 to increase the isolation of the transmission / reception signal. If the degree is good, the switch 8 is not always necessary.
Also, a signal of local oscillation frequency is not sent to the transmission side, a voltage-controlled oscillator that directly inputs data is provided, and it is configured to transmit without frequency conversion.When transmission is stopped, oscillation occurs instead of data. Transmission may be stopped by adding an offset voltage to the voltage controlled oscillator. The transmission / reception changeover switches 8 and 9 are switched in synchronization with the switching of transmission / reception bursts, and the control is performed by a transmission / reception control signal from a transmission / reception control unit provided in the digital signal processing circuit on the modulator / demodulator side.

FIG. 6 shows a configuration of a voice signal processing system and a transmitting / receiving section of a wireless communication system as another embodiment of the system of the present invention. An example of transmitting and receiving an audio signal is shown, and the same parts as those in FIGS. 3 and 4 are indicated by the same numbers, 21 is a data processing circuit, 22 is a transmitting unit, 23 is a receiving unit, and 24 is a clock reproducing circuit. is there.

Further, FIG. 7 is a time chart diagram showing signals of respective parts in the configuration of FIG. 6, where (a) is the output of the voice coder 12, (b) is the input of the voice decoder 15, and (c) is the transmission at the antenna 5. It shows a burst and a received burst.

In FIG. 6, the operation of the microphone 11 and the voice coder 12 is the fourth.
This is the same as the case of the figure, and FIG.
As shown in, the transmission voice data encoded at 16 kbps is generated. The data processing circuit 21 speed-converts and compresses the transmission voice data to generate the transmission data T, adds control data and forms a transmission burst of 48 kbps, and has the same configuration as in FIG. The signal is converted into a transmission frequency signal via the transmission unit 22 included therein, and is transmitted to the other side via the transmission / reception changeover switch 9 and the antenna 5, which is switched to the transmission unit 22 side based on the transmission / reception control signal from the data processing circuit 21. This produces the transmission burst shown in FIG. 7 (c).

As shown in FIG. 7 (c), the reception burst of 48 kbps from the other party consists of reception data R and control data, and is received from the transmission burst with a certain length of guard bit separated. In the reception burst period, the signal is received via the transmission / reception changeover switch 9 which is switched to the reception unit 23 side based on the transmission / reception control signal from the data processing circuit 21, and the reception unit 23 having the same configuration as in FIG. The speed is converted in the data processing circuit 21 to generate received voice data of 16 kbps as shown in FIG. 7 (b). The clock recovery circuit 24 recovers a clock from the received input data, and the data processing circuit 21 uses this clock to perform required data processing. The operations of the voice decoder 15 and the speaker 16 are the same as in the case of FIG. 4, and the voice signal is reproduced by this.

Regarding the synchronization between the two devices facing each other in the radio device shown in FIG. 6 and FIG. 7, the one that made the call first becomes the master station, and the other party becomes the slave station and synchronizes with the clock of the master station. It is done by working.

That is, the wireless device that became the master station does not perform clock recovery at the receiving part, but plays back the received data using the clock that is used at the transmitting side. The clock generating circuit generates the clock of its own station in synchronization with the clock reproduced from the signal and receives the clock, and at the time of transmission, the clock generating circuit is free-running to perform data transmission processing by this clock.

FIG. 8 shows the frame format of the transmission burst, and it is shown that it is composed of transmission data T and control data, and that the control data also includes a dotting pattern DP. It is shown.
The dotting pattern DP is provided for the slave station to synchronize with the clock of the master station. In the slave station, the clock recovery circuit in the slave station responds to the pulse extracted from the received dotting pattern DP by itself. The clock is generated by synchronizing the phase synchronization circuit of.

Furthermore, as the synchronization method in this case, the following two types of methods can be selected and used according to the distance between the two opposing devices.

(1) In the first synchronization method, transmission / reception bursts are sent out for communication without providing the guard bit shown in FIG. 7 (c). Now, assuming that the delay time from the master station transmitting unit to the slave station receiving unit and the delay time from the master station receiving unit to the slave station transmitting unit do not change, in the first synchronization method, The distance between them will be limited within the propagation distance of the delay time corresponding to 1 bit time. For example, if the bit rate of the transmission and reception bursts is 48 kbps as shown in FIG. 7, one cycle is 20.8 μs and the propagation distance is limited to about 6.2 km.

Although the service area is limited in the first synchronization method, there is an advantage that the circuit configuration of the synchronization system becomes simple.

(2) In the second synchronization method, the master station inserts the unique word UW shown in the frame format of FIG. 8 and sends out a burst, and when the slave station receives this, the unique word UW is also sent immediately. Returns the burst with the inserted.
The master station detects the position of the unique word UW in the slave station burst and compares it with the position of the unique word UW sent by itself to determine the round-trip propagation delay time with the slave station. Then, according to the magnitude of the delay time obtained,
The number of guard bits shown in the figure is determined, and in the subsequent master station burst, the guard bit thus determined is provided at the beginning or end of the burst and transmitted. In principle, the guard bit is unsigned.

Therefore, according to the second synchronization method, the service area can be set to an arbitrary distance by increasing or decreasing the number of guard bits.

〔The invention's effect〕

As described above, according to the wireless communication system of the present invention, since bursts are alternately transmitted and received between both devices to perform communication, bidirectional communication can be performed using a single frequency. Unlike the conventional two-way communication system, there is no need for a duplexer for separating a transmission frequency signal and a reception frequency signal. Moreover, since the transmission operation and the reception operation are performed alternately, no electromagnetic shield is required between the transmission unit and the reception unit. Therefore, the structure of the device is simplified, and the size and weight can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of a wireless communication system of the present invention, FIG. 2 is a diagram for explaining a time division directional control transmission system by radio, and FIG. 3 is a wireless communication system as an embodiment of the present invention. FIG. 4 is a diagram showing a configuration of a transmission / reception unit in a radio device, FIG. 4 is a diagram showing an example of a configuration of an audio signal processing unit system corresponding to the transmission / reception unit shown in FIG. 3, and FIG. 5 is shown in FIG. 6 is a time chart showing transmitted / received signals in the audio signal processing system, FIG. 6 is a diagram showing a configuration of an audio signal processing system and a transmitting / receiving unit of a wireless communication system as another embodiment of the present invention, and FIG. 7 is FIG. 8 is a time chart showing signals of each part in the configuration, FIG. 8 is a diagram showing a frame format of a transmission burst, FIG. 9 is a diagram showing a schematic configuration of a conventional two-way wireless communication system, and FIG. 10 is a conventional wireless system. It is a figure which shows the structural example of the transmission / reception part of a machine. 1 ... Transmission frequency conversion unit 2 ... High power amplifier (HPA) 3 ... Low noise amplifier (LPA) 4 ... Reception frequency conversion unit 5 ... Antenna 6 ... Transmission / reception duplexer 6A ... Transmission band filter 6B ... Reception band filter 6C ... Antenna Shared device (H) 7 ... Local oscillator 8,9 ... Transmission / reception switch 10 ... Band filter 11 ... Microphone 12 ... Voice coder 13,14 ... Velocity converter 15 ... Voice decoder 16 ... Speaker 21 ... Data processing circuit 22 ... Transmission unit 23 ... Receiving unit 24 ... Clock reproducing circuit A ... Radio base station B ... Radio equipment 101 ... Transmitting means 102 ... Receiving means 103 ... Clock reproducing means 104 ... Unique word sending means 105 ... Delay time measuring means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiko Kimura 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited (56) References JP-A-60-154736 (JP, A) JP-A-61-54732 (JP, A)

Claims (4)

[Claims] 1. In a wireless communication system for performing bidirectional communication between two opposing devices, a first device converts the digitized transmission information into a burst at a first timing that is repeatedly generated and outputs it. A first transmitting unit that modulates the frequency, further converts the frequency to a predetermined frequency, and transmits the second frequency; and a second transmission unit that is repeatedly generated unlike the first timing.
First receiving means for frequency-modulating, demodulating, and speed-converting the bursted information of a predetermined frequency received at the timing of 1 to reproduce the digitized transmission information, and connecting the antenna to the first receiving means. A switching device that connects to the first transmitting device side at a timing 1 and connects to the first receiving device side at a second timing is provided, and a second device facing the digital device transmits the digitized transmission information. Second transmission means for speed conversion, bursting at the second timing for output, modulation, frequency conversion to a predetermined frequency and transmission, and bursting for the predetermined frequency received at the first timing. Second receiving means for frequency-converting the demodulated information, demodulating, speed-converting it to reproduce digitized transmission information, and an antenna connected to the antenna at a second timing The switching means is connected to the second transmitting means side and is connected to the second receiving means side at a first timing, and the bursting is performed in a time division manner using a frequency common to transmission and reception between both devices. A wireless communication system characterized in that two-way communication is performed by alternately transmitting and receiving stored information. 2. A clock regenerating means for regenerating a clock from a received burst is provided in both devices, and the one of the two devices that has made a call first becomes a master station, and the master station transmits and receives in synchronization with its own clock. The wireless communication system according to claim 1, wherein the slave station transmits and receives in synchronization with a clock reproduced from the burst of the master station. 3. A delay time measurement for obtaining a delay time between both devices by comparing a unique word sending means for sending a unique word in a transmission burst with a unique word in a reception burst and a unique word sent by the own station. Means is provided, the slave station immediately returns the burst of its own station when it receives the burst of the master station, and the master station provides a guard bit of a length corresponding to the delay time obtained and sets the transmission burst of its own station. The wireless communication system according to claim 2, wherein transmission is performed. 4. A wireless communication system of a device which performs bidirectional communication with a device which is opposite to the device, which converts a speed of digitized transmission information and outputs a burst signal at a first timing which is repeatedly generated.
Speed converting means, modulating means for modulating the burst signal, transmitting means for frequency-converting the modulated signal into a signal of a predetermined frequency by a local oscillation frequency, and transmitting the signal, different from the first timing, repetitive Second to occur
A receiving means for receiving a signal of a predetermined frequency in a burst at a timing of, and converting the frequency by the local oscillation frequency; a demodulating means for demodulating the frequency-converted signal; and a second means for speed-converting the demodulated signal. And the second timing so that the signal from the transmission means is output via the antenna at the first timing,
A control means for controlling the receiving means to receive a signal via the antenna, and alternately transmitting and receiving the bursted information in a time division manner by using a frequency common to transmission and reception, and bidirectional communication with the opposite device. A wireless communication system characterized by performing.