JPH08139708A - Radio receiver and radio communication system - Google Patents

Abstract

PURPOSE: To provide a radio telephoneset and a radio telephone system which can perform the duplex transmission of call data by means of the idle channels of communication slots and can prevent the deterioration of transmission quality for the call data. CONSTITUTION: The received speech signal data (a) and (b) on the 2nd and 4th slots are extracted at a TDM processing part 5 and stored in the 2nd and 4th slot data memories 5a and 5b respectively. Then an error detection part 5c detects the errors of both data (a) and (b) and outputs each error detection signal to a data selection part 5d in response to the number of detected errors. The part 5d compares the numbers of errors with each other between the data (a) and (b) based on the error detection signals. Then a built-in switch is changed over to the data having a smaller number of errors. Thus stored data (a) and (b) are alternatively selected and read out, and the selected data (c) is outputted to a voice codec part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless receiver and a wireless communication system suitable for application to a personal handyphone system, and more particularly to a wireless receiver and a wireless communication system for improving call quality. Regarding

[0002]

2. Description of the Related Art Recently, with the rapid progress of digital technology, mobile communication systems are also shifting from analog communication systems to digital communication systems. In mobile communication systems, transmission and reception of control signals between base stations and mobile devices is essential, but by using digital signals for these control signals, we have constructed a basic system that realizes high-efficiency and high-quality wireless transmission. can do. In addition, the application of digital technology in a mobile communication system enables downsizing of a base station and a mobile device, and makes it easier to carry the mobile device.

Therefore, in recent years, the number of mobile phones and cordless phones as mobile units has been rapidly increasing.
However, in the conventional analog system, it is difficult to cope with the increase in the number of subscribers due to the limitation of the allocation of the used frequency, and the confidentiality is difficult, and there is a problem in the use for business use. Therefore, in order to solve these problems of the analog system, a digital mobile phone using a wide range of digital technology has been introduced, and a personal handyphone system is being studied.

This personal handyphone system (hereinafter referred to as PHS) limits the use area of a mobile device to a small zone called a microcell, enables repeated use of frequencies, and creates an enormous number of channels. It is a system that effectively utilizes the frequency resources. Also, since the zone (also called cell) is made small, the transmission output of the mobile device may be small, which helps to miniaturize the mobile device, consumes less power, reduces the battery size, and has a long operating time. Also helps.

In PHS, the radio transmission system between the base station and the terminal is the Radio System Development Center (hereinafter referred to as R
RCR-STD-28
Is standardized as. This wireless transmission system uses TDM
A (Time Division Multiple Access) -TDD (Time D
ivision Duplex), for example, data is transmitted and received between a base station and a terminal in the transmission mode shown in FIG.

That is, in FIG. 6, four Telecommunication channels (communication slots indicated by 1 to 4 in the figure) are secured by the TDMA (time division multiple access) method, and T
Transmitting signal data and receiving signal data are transmitted and received at the same frequency in a time division manner by the DD method. In the case of FIG. 6, the first slot is the control channel (CCH: Control Chann-e).
It is used as l) and is used to inform control information related to data transmission when the base station transmits data to the terminal.

The second slot in FIG. 6 is used as a traffic channel (TCH: Traffic Chnnel). In the case of a call, voice data is transmitted and received between the base station and the terminal, and in the case of data transmission, the data is transmitted. It is transmitted and received between the base station and the terminal. As shown in FIG. 6, the base station transmission is synchronized with the terminal reception, and the terminal transmission is synchronized with the base station reception. In this case, the first slot is used intermittently, for example, once every 100 msec, the second slot is always used, and the third slot and the fourth slot are not used as empty channels. .

[0008]

However, in the TDMA-TDD system as a wireless transmission system used between the base station and the terminal in such a conventional PHS, for example, as shown in FIG. In addition, since 1 channel is set as a control channel among the communication slots set for 4 channels and 1 channel is assigned as a call channel for wireless transmission / reception of call data, noise is generated in the transmitted / received radio waves due to the influence of disturbance or the like. if you did this,
There is a problem that the transmission quality of call data is likely to deteriorate.

An object of the present invention is to provide a wireless receiver and a wireless communication system which prevent the deterioration of the transmission quality of call data by redundantly transmitting call data by utilizing an empty channel of a communication slot.

[0010]

According to the first aspect of the present invention,
In a wireless receiver capable of transmitting and receiving a call signal to and from a destination telephone by wireless communication using a communication slot with a transmitter, a transmission signal redundantly transmitted from the transmitter using the communication slot Receiving means for receiving data, data error detecting means for detecting a data error for each identical received signal data in the communication slot received by the receiving means in duplicate, and each identical received signal detected by the data error detecting means Selective output means for comparing the data error amounts of the data and selecting and outputting the received signal data having a small data error amount.

According to a second aspect of the present invention, in a wireless communication system capable of transmitting / receiving a transmission / reception signal by utilizing a plurality of communication slots by wireless communication between the base station and the terminal, the base station and the terminal respectively Transmission means for wirelessly transmitting the transmission signal data to the other by using the communication slot, reception means for receiving the transmission signal data which is transmitted in duplicate from the other transmission means, and duplicate reception by this reception means The data error detection means for detecting a data error for each identical reception signal data is compared with the data error amount of each identical reception signal data detected by this data error detection means, and the reception signal data with a small data error amount is selected. And a selective output means for outputting the output.

Further, in this case, as described in claim 3, when the same transmission signal data is redundantly transmitted in the communication slot by the time division structure, the transmitting means separates the respective communication slots from each other. Is effective.

[0013]

According to the invention as set forth in claim 1, in a wireless receiver capable of transmitting and receiving a call signal to and from a destination telephone by wireless communication using a communication slot with the transmitter, the transmitter When the receiving means receives the transmission signal data that is redundantly transmitted from the
The data error detection means detects a data error for each identical reception signal data in the communication slots that have been redundantly received, and the selective output means compares the detected data error amounts of the same reception signal data to obtain the data error amount. Selects and outputs the received signal data with a small number.

Therefore, it is possible to reduce the influence of the change in the radio wave state on the reception signal data transmission, and it is possible to improve the transmission quality of the wireless transmission line in the wireless telephone.

According to a second aspect of the present invention, in a wireless communication system capable of transmitting / receiving a transmission / reception signal using a plurality of communication slots by wireless communication between the base station and the terminal, the base station and the terminal are , And each of the transmitting means wirelessly transmits the transmission signal data to the other by duplicating the transmission signal data using the communication slot, and when the receiving means receives the transmission signal data redundantly transmitted from the other transmission means, the data error detection means , A data error is detected for each of the same received signal data that is received redundantly, and the selective output means compares the detected data error amounts of the same received signal data and selects the received signal data with a small data error amount. Output.

Therefore, it is possible to reduce the influence of the change in the radio wave state on the reception signal data transmission, and it is possible to improve the transmission quality of the wireless transmission path between the master unit and the slave unit in the wireless telephone system.

According to the third aspect of the present invention, when the same transmission signal data is redundantly transmitted in the communication slot by the time division structure, the transmitting means separates the respective communication slots to transmit the same reception. It is possible to easily set the mode in which the signal data is redundantly transmitted.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below in detail with reference to FIGS. 1 to 5 are views showing an embodiment in which the present invention is applied to PHS. First, the configuration will be described. FIG.
FIG. 3 is a block configuration diagram of a main part of the mobile phone 1. In FIG. 1, a mobile phone 1 includes an antenna 2, a transmitting / receiving unit 3,
It is composed of a modem 4, a TDMA processing unit 5, a voice codec unit 6, a transmission / reception unit 7, a CPU 8, an operation unit 9, and a display unit 10.

The antenna 2 sends / receives a sending / receiving signal including a calling signal and a voice signal in a predetermined frequency band to / from a home base unit (not shown) or a public wireless base station, and sends / receives a receiving signal. The transmission signal is output to the unit 3 and the transmission signal input from the transmission / reception unit 3 is transmitted.

The transmitting / receiving unit 3 frequency-converts a transmission signal input from the modem 4 into a transmission signal of a predetermined radio frequency from the antenna 2 in order to wirelessly transmit the transmission signal to the home base unit or the public radio base station. The received signal, which is transmitted and received from the home base station or the public wireless base station by the antenna 2, is frequency-converted into an intermediate frequency and output to the modem 4. The modem 4 modulates the transmission data input from the TDMA processing unit 5 and outputs the transmission signal to the transmission / reception unit 3, and demodulates the reception signal input from the transmission / reception unit 3 to receive the reception data. Output to the TDMA processing unit 5.

The TDMA processing unit 5 transmits / receives a transmission / reception voice signal between the modem 4 and the voice codec unit 6, and
A communication control signal is exchanged with the CPU 8 to extract actual data of digital data received in a predetermined time slot, and a header section input from the CPU 8 is added to digital audio data input from the audio codec section 6. Then, the data is converted into a predetermined data format, inserted into a predetermined time slot, and output to the modem 4.

In addition, TDMA (Time Division Multiplexing)
As shown in FIG. 2, the access) processing unit 5 has slot data memories 5a and 5b, an error detection unit 5c, and a data selection unit 5d on the receiving side. Slot data memory 5
a is a predetermined slot data a (call data) received by using a predetermined slot (for example, the second slot) in the communication slots shown in FIG. 6 to temporarily store the error detection unit 5c and the data. The slot data memory 5b outputs the data to the selection unit 5d and temporarily stores the slot data b (call data) transmitted using another slot (for example, the fourth slot) in the communication slots of the same frequency. And outputs it to the error detector 5c and the data selector 5d.

The error detector 5c detects an error in the slot data a and the slot data b respectively stored in the slot data memory 5a and the slot data memory 5b, and compares the detected error amounts of the respective slot data a and b. Then, the switching signal according to this error amount is output to the data selection unit 5d.

Based on this switching signal, the data selection unit 5d switches the built-in switch 5d to the one having the smaller error amount, thereby the slot data a and the slot data stored in the slot data memory 5a and the slot data memory 5b, respectively. b is alternatively selected and read, and the read reception signal data c is read by the voice codec unit 6
Output to.

On the transmission side, the slot data memories 5e and 5f respectively corresponding to the slot data memories 5a and 5b are incorporated. The transmission signal data d input from the audio codec unit 6 is stored in the slot data memory 5e,
The slot data memory 5e, which is temporarily stored in 5f,
The slot data corresponding to the slot data memory 5a, that is, the predetermined slot data e (call data) transmitted using the predetermined slot (for example, the second slot) in the communication slots shown in FIG. The memory 5e outputs the predetermined slot data f transmitted using the slot timing corresponding to the slot data memory 5b, that is, the predetermined slot (for example, the fourth slot) in the communication slots shown in FIG.

The voice codec section 6 includes a changeover switch 6
a, 6b, 32 kbps ADPCM compression / expansion device 6
c, 16 kbps compression / expansion device 6d, 8 kbps compression / expansion device 6e, and PCM codec unit 6f. The changeover switches 6a and 6b are controlled to be switched by the CPU 8 and are 32 kbps ADPCM compression / expansion devices 6c and 16 kb for compressing / expanding the transmission signal data.
ps compression / expansion device 6d, 8kbps compression / expansion device 6
Select e.

32 kbps ADPCM compression / expansion device 6
c is an ADPCM (Adaptive Differential Pulse Code Mod) for transmitting a transmission signal input from the PCM codec unit 6f.
ula-tion: compression (encoding) with adaptive differential pulse code modulation)
Then, the compressed reception signal input from the TDMA processing unit 5 is expanded (decoded) and output to the PCM codec unit 6f. This 32
The kbpsADPCM compression / decompression device 6c is a standard RCR encoding method.

Similarly, a 16 kbps compression / expansion device 6d
The 8 kbps compression / decompression device 6e compresses (encodes) the transmission signal input from the PCM codec unit 6f by a predetermined encoding method, outputs the compressed transmission signal to the TDMA processing unit 5, and inputs the transmission signal from the TDMA processing unit 5. The compressed reception signal is expanded (decoded) and output to the PCM codec unit 6f.

The PCM codec section 6f is 32 kbps.
The compressed reception signal input through the ADPCM compression / expansion device 6c, 16 kbps compression / expansion device 6d, and 8 kbps compression / expansion device 6e is A / D converted and output to the transmission / reception unit 7, and also from the transmission / reception unit 7. 32 kbps ADPCM compression / expansion device 6c, 1
The data is output to the 6 kbps compression / expansion device 6d and the 8 kbps compression / expansion device 6e. CPU (Central Processing Uni
t) 8 controls each part in the mobile phone 1 by various control programs stored in a ROM (Read Only Memory) to execute the sequence as the mobile phone 1 in the PHS, and is issued by an off-hook operation of the operation part 9. TDMA processing unit 5 depending on the call request and the telephone number of the other party who is key-in
A call setting request or the like is output to the device, the communication control sequence is executed, the key input information and the information indicating the communication state during the call are displayed on the display unit 10, and the call is made by the microphone and speaker of the handset unit 7. Control as much as possible, and
Based on the communication control information input from the DMA processing unit 5, a control signal for switching the changeover switches 6a and 6b in the audio codec unit 6 is output to output 32 kbps ADPC.
M compression / expansion device 6c, 16 kbps compression / expansion device 6
d, 8 kbps compression / expansion device 6e is selected.

The operation unit 9 is provided with a hook key, a ten key, various mode keys and the like, and outputs a call request, a telephone number of the called party, etc., which are keyed in by the user, to the CPU 8. The display unit 10 is composed of a liquid crystal display panel or the like, and displays key input information input from the CPU 8 and a communication state during a call. Note that the configuration of the home base unit or the public wireless base station is basically the same as that of the mobile phone 1, and the configuration for connecting to the telephone line is greatly different.

Next, the operation will be described. First, a case will be described in which a call process between the mobile telephone 1 of the present embodiment and the other party's mobile telephone in the PHS is performed via a home base station or a public wireless base station.

In the Hong embodiment, 32 kbps AD is used.
Communication mode by PCM (standard, duplicate), 16 kbps
Communication mode by encoding (standard, duplicate) and 8 kbps
It is possible to select the mode based on the compression rate of each of the communication modes (standard and overlapping) by encoding. First, 32
The kbps duplication mode will be described. It should be noted that in this embodiment, a split call is explained, but basically the same applies to a collective call.

First, the operation unit 9 of the mobile telephone 1 is used to set 32
Off hook (OFF) by specifying the kbps duplication mode
When the HOOK) operation is performed, a communication control sequence based on a wireless communication protocol by the CPU 8 is started, and a link channel establishment request is issued from the TDMA processing unit 5 using the control channel (for example, the first slot of a predetermined frequency). Device or public wireless base station. This time,
Data designating a 32 kbps duplication mode is added to the link channel establishment request and transmitted.

In the home base unit or the public wireless base station,
When the link channel establishment request is received from the mobile telephone 1, the ID from the terminal is authenticated, the empty call channel based on the duplicate mode is searched for two slots, and 2
If there is an empty speech channel in a slot (for example, the second slot and the fourth slot on the same frequency shown in FIG. 3),
The link channel assignment is transmitted to the mobile phone 1.

Based on this, the mobile telephone 1 and the home base unit or the public base station move to the call channel and execute the processing of the service channel establishment phase. The processing in this case (processing relating to the control signal) may be executed using only one slot of the two allocated speech slots, or may be executed using two slots.

Next, by operating the dial keys of the operation unit 9 of the mobile telephone 1, the dial number for calling the partner telephone is input, and the telephone number is transmitted to the home base unit or the public wireless base station. To do.

In response to this, the in-home base unit or the public wireless base station transmits this telephone number to the exchange to be connected to the partner's telephone, and the call is started. At this time, for example, as shown in FIG. 3, the second slot and the third slot on the same frequency are used.

First, at the time of transmission from the home base unit or the public radio base station (T in FIG. 3A), the same voice data is transmitted using the second slot and the third slot. At this time, the mobile phone 1 side receives (R in FIG. 3B)
Thus, the audio data of the second slot and the fourth slot are temporarily stored in the slot data memories 5a and 5b, respectively, and the audio data c of which the switch is switched is output to the audio codec 6 via the data selection unit 5d. The error detection unit 5c
The error amount of each data is detected by the data selection unit 5 and a selection signal for selecting which audio data is output at the next reception based on each error amount is output.
The data selection section 5d receives the selection signal and switches the switch.

At the time of transmission of the mobile telephone 1 (FIG. 3 (b))
When the voice data d input from the voice codec 6 is input to T) of the slot data memory 5e, 5
The same audio data d is temporarily stored in each f, and the audio data is output at a predetermined timing, for example, the timing of the second and fourth slots. This audio data is TDM
After being A-processed, it is transmitted to the home base unit or the public wireless base station. At this time, in the home base unit or the public wireless base station, it becomes the reception time (R in FIG. 3A), and the voice data of the received voice data having the smaller error amount is transmitted via the telephone line to the other party's telephone. Send to.

As described above, when a call is made between the mobile telephone 1 of the present embodiment and the destination telephone when the call is made via the home base unit or the public radio base station, the empty channel of the call slot is used. Then, the same transmission signal data and reception signal data are transmitted and received in duplicate, and the mobile telephone 1,
In the home base unit or the public wireless base station, the reception signal data of the channel with the smaller error amount is selected and output.

Therefore, even if the radio wave condition changes and the reception signal data is affected by noise or the like, the reception signal data with a small error amount can always be transmitted, and in the second cordless telephone system and the mobile telephone 1. The transmission quality of voice data can be improved.

In order to transmit / receive the same voice data at different timings, it is possible that the voice data is switched from the previous voice data or overlaps with the previous voice data when the voice data is switched. Regarding the delay, there is a blank between the previous and current audio data, but I think that there is no problem. Regarding duplication, it is possible to avoid duplication by giving priority to the present audio data for the overlapping portion of the previous and present audio data.

Further, the home base unit or the public radio base station which is the base station can inform other mobile telephones (slave units) of the duplicate transmission / reception processing mode by the control slot CCH. Furthermore, in the above-described embodiment, the communication of voice data has been described, but not limited to voice data, image data or text data may be used.

In the embodiment of the phone, 32 kbps ADPC, which is a standard of RCR (Radio System Development Center), is used.
16 kbps and 8 kbp in addition to M format compression / expansion
Since the s compression / expansion device is provided, the present invention can be applied to these systems.

First, the 16 kbps standard mode will be described. 16 kbps companding method (encoding method is ADPC
(Not limited to M), 32 kbps ADPCM system 1
Since the amount of data is / 2, as shown in FIG. 4, the number of slots is 1/2 that of the 32 kbps coding method. That is, the next transmission timing transmitted at a predetermined timing (after 5 ms)
Then, the data is not transmitted, and the next transmission is performed at the next transmission timing (10 ms later) (the transmission cycle is 1
0 ms).

Even in such an overlapping mode of the 16 kbps coding system, the same operation as the 32 kbps coding system can be performed. That is, as shown in FIG. 5, the duplication mode is realized by transmitting the same data as the data transmitted last time at the data non-transmission timing of FIG. In this case 3
Data recovery is worse than the 2 kbps code, but it can be realized using one slot.

Also, the same can be realized in the 8 kbps coding system. That is, in this case, since the transmission cycle in the standard mode is 20 ms, there are three data non-transmission timings. The same data may be transmitted for all three non-transmission timings, or the same data may be transmitted for only one (in this case, any data non-transmission timing may be used).

By doing so, compared to the case of using the fourth slot in the same communication slot as shown in the above embodiment, the transmission cycle of the overlapping slot can be separated by 5 msec, so that the radio wave condition can be obtained by the effect of the time shift. It is possible to further reduce the influence of the change of the above, and it is possible to further improve the transmission quality.

These settings are performed by exchanging information regarding the compression process between the mobile telephone 1 (slave unit) and the home base unit or the public wireless base station as the base station by the control channel CCH or SACCH. The mode is selected correctly. That is, the standard compression method is automatically selected between the standard-type device and the standard-type device, which does not hinder the call.

In the above embodiment, TDD-TDMA is used.
Although the example applied to the communication system has been shown, it is needless to say that the present invention is not limited to this and can also be applied to a communication system in which frequencies are different for transmission and reception.

[0051]

According to the first aspect of the present invention, it is possible to reduce the influence of the change in the radio wave condition on the reception signal data transmission, and it is possible to improve the transmission quality of the wireless transmission line in the wireless telephone.

According to the second aspect of the present invention, it is possible to reduce the influence on the received signal data transmission due to the change of the radio wave state, and the transmission quality of the wireless transmission line between the base station and the slave unit in the wireless telephone system. Can be improved.

According to the third aspect of the invention, it is possible to easily set the mode in which the same reception signal data is redundantly transmitted.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of a mobile phone to which a wireless phone of the present invention is applied.

FIG. 2 is a block diagram of a main part in the TDMA processing unit of FIG.

FIG. 3 is a 32 kbps ADP between the mobile telephone of this embodiment and a home base unit or a public wireless base station which is a base station.
The figure which shows the transmission / reception form of the call data duplicated at the data processing speed of CM.

FIG. 4 shows transmission / reception of call data that is standardly transmitted / received at a data processing speed of 16 kbps compression between the mobile telephone of this embodiment and a home base unit or a public wireless base station which is a base station.
The figure which shows a reception form.

FIG. 5: Transmission / reception of call data which is redundantly transmitted / received at a data processing speed of 16 kbps compression between the mobile telephone of this embodiment and a home base unit or a public wireless base station which is a base station.
The figure which shows a reception form.

FIG. 6 is a diagram showing a transmission / reception mode of call data transmitted / received between a conventional mobile phone and a base station.

[Explanation of symbols]

 1 Mobile Phone 2 Antenna 3 Transmitter / Receiver 4 Modem 5 TDMA Processor 5a Slot Data Memory 5b Slot Data Memory 5c Error Detector 5d Data Selector 5e Slot Data Memory 5f Slot Data Memory 6 Voice Codec 6a Changeover Switch 6b Changeover Switch 6c 32 kbps ADPCM compression device 6d 16 kbps compression device 6e 8 kbps compression device 7 handset 8 CPU 9 operation unit 10 display unit

Claims (3)

[Claims] 1. A wireless receiver capable of transmitting / receiving a call signal to / from a partner telephone by wireless communication with a transmitter using a communication slot, wherein the transmitter uses the communication slot to duplicate. Receiving means for receiving the transmission signal data to be transmitted, data error detecting means for detecting a data error for each identical reception signal data in the communication slot received by the receiving means in duplicate, and data error detecting means for detecting the data error. And a selection output unit that compares the data error amounts of the same received signal data and selects and outputs the received signal data having a small data error amount. 2. A wireless communication system capable of transmitting / receiving a transmission / reception signal by using a plurality of communication slots by wireless communication between a base station and a terminal, wherein the base station and the terminal respectively use the communication slots. And transmitting means for wirelessly transmitting the transmission signal data to the other by means of one another, receiving means for receiving the transmission signal data which is redundantly transmitted from the other transmitting means, and for each identical reception signal data which has been redundantly received by this receiving means. Selective output means for comparing the data error amount detecting means for detecting a data error with the data error amount of each identical reception signal data detected by the data error detecting means and selecting and outputting the reception signal data having a small data error amount. And a wireless communication system comprising: 3. The transmitting means, when the same transmission signal data is redundantly transmitted in a time division configuration in the communication slot,
The wireless communication system according to claim 2, wherein the respective communication slots are transmitted separately.