JPH08251229A - Radio communication system - Google Patents

Abstract

PURPOSE: To provide a radio communication system with which audio signals and data signals can be efficiently transmitted by transmitting information in a radio access system with packet communication. CONSTITUTION: Concerning the radio communication system provided with a transmitter 10 and a receiver 20 for performing radio communication, the transmitter 10 generates an audio packet from the sounded part of the audio signal by using an audio packet processing means 11, generates a data packet from the data existing part of the data signal by using a data packet processing means 12 and transmits these respective packets to the receiver 20 according to the order decided by an audio/data arbitrating means 13. On the other hand, the receiver 20 reproduces the received audio packet into the audio signal by using an audio signal reproducing means 24 and reproduces the received data packet into the data signal by using a data signal reproducing means 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system for wirelessly communicating a voice signal for a call and a data signal for a data communication.

[0002]

2. Description of the Related Art Conventional wireless communication systems include, for example, "NTT REVIEW, Vol. 4, No. 1, januar.
y 1992, pp. 47-54 "Radio Link Control Techniques for Digital
Cellular Systems) ”, time division multiple access (TDMA).
le Access) type cellular mobile communication systems are known. This cellular mobile communication system is composed of a combination of a wired communication network such as a public line and a wireless access system for performing wireless communication.

In the wireless access system, information is transmitted and received wirelessly between a base station connected to a wired communication network and a mobile station such as a mobile phone or an information portable terminal device. The information transmitted and received by the wireless access system includes a voice signal for a call and a data signal for data communication (for example, communication of image information). Furthermore, in this wireless access system, when transmitting and receiving information, transmission based on circuit switching is performed. Circuit switching means that when a communication channel for transmitting information between a sender and a receiver is established, the communication channel is continuously occupied from the call setting at the start of transmission to the call release at the end of transmission. The information transmitted on the occupied communication channel is stored in a fixed length transmission frame as shown in FIG. 7 and sent from the transmitting side to the receiving side.

[0004]

However, in the radio access system in the above-mentioned radio communication system, since transmission based on circuit switching is performed, for example, a silent part in a voice signal or no data in a data signal is present. Even unnecessary information such as parts is stored in a transmission frame and transmitted, and as a result, efficient transmission cannot be performed. In addition, in transmission based on circuit switching, when one communication channel is established, it is not possible to interrupt another communication channel until the call of that communication channel is released, so that the other communication channel is different from the established communication channel. Even when trying to transmit a signal (for example, a data signal for a voice signal), it is necessary to wait until the call of the established communication channel is released, and as a result, efficient transmission cannot be performed.

In particular, since the types of frequencies that can be used in wireless communication are limited, the obstacle to efficient information transmission is an increase in the number of mobile stations transmitting information (for example, an increase in the number of subscribers to mobile phones). Will interfere with the response. Therefore, it is an object of the present invention to provide a wireless communication system capable of efficiently transmitting a voice signal and a data signal by transmitting information by packet communication in a wireless access system.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a wireless communication system devised to achieve the above object, in which voice signals for communication and / or data signals for data communication are input. Then, a transmitter for wirelessly transmitting the input signal, and a receiver for receiving and outputting the voice signal and the data signal from the transmitter, the transmitter further comprising: The apparatus divides a voiced part of the voice signal into a predetermined unit to generate a voice packet, and a data packet part of the data signal into a predetermined unit to generate a data packet. Data packet processing means, and the transmission of each of the voice packet divided by the voice packet processing means and the data packet divided by the data packet processing means. And the audio data arbitration means for determining the order of transmission means for transmitting said data packets and said audio packets to the receiving device is provided according to the order determined by the speech data arbitration means, whereas,
The receiving device includes receiving means for receiving the voice packet and the data packet from the transmitting means, and a voice for discriminating whether the one received by the receiving means is the voice packet or the data packet. Data identifying means, voice signal reproducing means for reproducing the voice packet identified by the voice / data identifying means as the voice signal, and the data packet identified by the voice / data identifying means as the data signal A data signal reproducing means for reproducing is provided.

[0007]

According to the above-mentioned structure, the following operation is achieved. When a voice signal is input to the transmitter, the voice packet processing means divides only the voiced portion of the voice signal to generate a voice packet. When a data signal is input to the transmitter, the data packet processing means
A data packet is generated by dividing only the data-containing portion of this data signal. When a voice packet is generated by the voice packet processing means and a data packet is generated by the data packet processing means, the voice / data arbitration means determines the order of transmitting these voice packet and data packet to the receiving device. Then, when the order is determined by the voice / data arbitration means, the transmitting means transmits the voice packet or the data packet according to the order. On the other hand, in the receiving device, when the receiving means receives the voice packet or the data packet from the transmitting means, the voice / data identifying means identifies whether the received packet is a voice packet or a data packet. voice·
When the data identifying means identifies the voice packet, the voice signal reproducing means reproduces the voice signal before division from the voice packet. When the voice / data identifying means identifies the data packet, the data signal reproducing means reproduces the data signal before division from the data packet. Therefore, between the transmitting device and the receiving device, only the voiced portion of the voice signal and the data present portion of the data signal are packetized and transmitted. Further, in these transmissions, the transmission order of the packets is determined by the voice / data arbitration means, so that it is possible to transmit the data packets during a period corresponding to a silent portion of the voice signal, for example.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wireless communication system according to the present invention will be described below with reference to the drawings. The wireless communication system of the present embodiment includes a base station (Base Station) 10 and a mobile station (Mobile Station) 20 as shown in FIG. 1, and as shown in FIG. 30 and a wireless access system. Wired communication network 3
0 is provided with an exchange 31, a base control station 32, and a plurality of base stations 10, 10a, 10b, ....

The exchange 31 is, for example, a public line or ISD.
It is connected to another exchange through a network such as N (Integrated Services Digital Network), and exchanges voice signals for calls and data signals for data communication with the other exchanges. It is a thing.
The base station 32 includes a plurality of base stations 10, 10a, 10b.
It manages and controls ... Multiple base stations 1
0, 10a, 10b, ... Are connected to the exchange 31 by wire via the base control station 32, respectively.

On the other hand, the radio access system is composed of base stations 10, 1
0a, 10b, ... Are connected to mobile stations 20, 20a, ..., Which are composed of mobile phones, portable information terminals, etc., and each base station 10, 10a, 10b ,.
Voice signals and data signals are transmitted and received to and from 20a ... Here, the base station 10 and the mobile station 20 in this radio access system will be described in detail with reference to FIG. Here, for simplification of description, one base station 10 to one mobile station 2
The case of transmitting a voice signal and a data signal to 0 will be described. That is, hereinafter, the base station 10 is the transmitting device 10 of the present invention, and the mobile station 20 is the receiving device 2 of the present invention.
It will be described as 0.

The transmitting device 10 includes a voice packet processing means 1
1, a data packet processing means 12, a voice / data arbitration means 13, a frame buffer means 14, and a transmission means 15. The voice packet processing means 11, the data packet processing means 12, the voice / data arbitration means 13, and the transmitting means 15 are each composed of a microprocessor or the like, and the frame buffer means 1
Reference numeral 4 is a semiconductor memory (for example, RAM) or the like.

As shown in FIG. 3, the voice packet processing means 11 divides only the voiced portion of the voice signal from the wired communication network 30 and stores a short packet (voice packet) for storing the divided voice signal. ) Is generated. This voice packet has a fixed length shorter than the transmission frame length in the conventional circuit switching, and consists of an information part and a header part. The information part of the voice packet stores the voice signal after division. The header part of a voice packet is composed of a packet type, a packet sequence number, and packet additional information.

The packet type is information indicating the type of this short packet. That is, information indicating that this short packet is a voice packet is stored in the packet type of the voice packet. The packet sequential number is information indicating which part of the audio signal stored in the information part corresponds to before the division. this is,
It is indicated by a sequential number given when the voice signal is divided by the voice packet processing means 11. The packet additional information represents the additional information of this short packet and is, for example, information indicating the time length of the silent portion of the audio signal. The information indicating the time length of the silent portion is stored in the voice packet immediately before the silent portion starts.

Further, in FIG. 1, the data packet processing means 12 divides only a portion with data (a portion with data content) in the data signal from the wired communication network 30 and stores the divided data signal. A short packet (data packet) is generated for this purpose. This data packet has a fixed length shorter than the transmission frame length in the conventional circuit switching, and, like a voice packet, is composed of an information part and a header part. However, information indicating that this short packet is a data packet is stored in the packet type of the data packet. Further, the packet addition information of the data packet stores an error detection code for each data packet.

The voice / data arbitration means 13 receives voice packets from the voice packet processing means 11 or data packets from the data packet processing means 12 and transmits them to the receiving device 20 in the order of packet sequence numbers. After it is determined, it is sent to the frame buffer means 14. The voice / data arbitration unit 13 is provided with a priority process determining unit 13a in case that a voice packet and a data packet are received at the same time. The priority processing determining means 13a determines to give priority to a voice packet that requires immediacy with respect to a data packet that does not require immediacy. ,
Even after the audio signal is divided and transmitted to the receiving device 20,
The synchronism with the time length of the voiced part of the audio signal before division is ensured.

The frame buffer means 14 receives the voice packet and the data packet from the voice / data arbitration means 13 and temporarily stores them. The transmitting means 15 takes out short packets (voice packets or data packets) to be transmitted from the frame buffer means 14 according to the order determined by the voice / data arbitration means 13, and wirelessly communicates them via the transmitting antenna 15a with the receiving device 20. Is to be sent to. In addition, the transmission means 15
It has a function of retransmitting a data packet in accordance with a request from a retransmission request processing means 26b described later.

On the other hand, the receiving device 20 includes receiving means 21 and
The audio / data identifying means 22, the audio frame buffer means 23, the audio signal reproducing means 24, the data frame buffer means 25, and the data signal reproducing means 26 are provided. The receiving means 21, the voice / data identifying means 22, the voice signal reproducing means 24, and the data signal reproducing means 26.
Are each composed of a microprocessor or the like, and the audio frame buffer means 23 and the data frame buffer means 25 are composed of a semiconductor memory (for example, RAM) or the like.

The receiving means 21 receives short packets transmitted by radio communication from the transmitting means 15 of the transmitting apparatus 10 via the receiving antenna 21a. The voice / data identifying means 22 identifies the short packet received by the receiving means 21 according to the packet type of each header part, and when the identification result is a voice packet, the voice / data identifying means 22 sends it to the voice frame buffer means 23, and the identification result is data. If it is a packet, it is sent to the data frame buffer means 25. The audio frame buffer means 23,
The voice packet from the voice / data identification means 22 is temporarily stored.

When the audio signal reproducing means 24 accumulates in the audio frame buffer means 23 all the audio packets corresponding to the voiced part of the audio signal before division, that is, the audio packets up to immediately before the silent part of the audio signal. , As a voice signal according to the packet sequence number. The audio signal reproducing means 24 is provided with a waveform replacement processing means 24a in case the audio packet is lost due to deterioration of the wireless transmission path or the like. The waveform replacement processing means 24a is for complementing the missing voice packet and has the following functions. As shown in FIG. 4, from the voice packets immediately before the missing voice packet, The pitch period of the voice signal before division is calculated, and the voice waveform is extracted from the voice packets up to immediately before. Then, for the portion where the voice packet is further lost, the extracted voice waveform is replaced based on the calculated pitch period, so that the voice signal is reproduced. The audio signal reproducing means 2
The audio signal reproduced in 4 is the audio signal output means 24b.
(For example, a speaker or the like).

In FIG. 1, the data frame buffer means 25 temporarily stores the data packet from the voice / data identification means 22. The data signal reproducing means 26 reproduces as a data signal according to the sequential number stored in the packet sequential number when the data packet corresponding to the data existing portion of the data signal before division is accumulated in the data frame buffer means 25. Is. Further, the data signal reproducing means 26 is provided with a retransmission request processing means 26a in case a data packet is lost due to deterioration of a wireless transmission path during wireless communication.

The retransmission request processing means 26a is for complementing the missing data packet. However, the retransmission request processing means 26a cannot complement the data packet by waveform replacement like a voice packet. Therefore, when a transmission error is found based on the error detection code stored in the packet additional information of the data packet, The transmission means 15 is requested to retransmit the missing data packet. The data signal reproduced by the resend request processing means 26a is sent to an external device 33 such as a personal computer (abbreviated as PC in the figure) via the modem 27, and is output by the external device 33. There is.

Next, the basic operation of the radio communication system configured as described above will be described. First,
As shown in the flow chart of FIG. 5, when a voice signal is sent from the wired communication network 30 to the transmitting device 10 (step 101, step is hereinafter abbreviated as S), the voice packet processing means 11 detects the presence of this voice signal. Only the sound part is divided to generate a voice packet (S102). In this voice packet, information indicating that the packet type is a voice packet is stored, and a sequential number when the voiced portion is divided into packet sequential numbers is stored. Further, in the voice packet corresponding to the end of the voiced portion (voice packet immediately before the voiceless portion), information indicating the time length of the voiceless portion is stored in the packet additional information.

When a data signal is sent from the wired communication network 30 to the transmitting device 10 (S103), the data packet processing means 12 divides only the data present portion of the data signal to generate a data packet. Yes (S10
4). As in the case of voice packets, this data packet stores information indicating that it is a data packet in the packet type, and the sequential number when the effective part is divided into packet sequential numbers. The error detection code is stored in the additional information. These voice packets and data packets are used as voice / data arbitration means 13
The transmission order when transmitting to the receiving device 20 is determined by (S105). This transmission order is determined according to the packet sequence number between voice packets and between data packets. Further, between the voice packet and the data packet, the priority decision deciding means 13a.
Voice packets are prioritized by, for example, a data packet is transmitted between silence parts when there is a silence part in the voice signal, and a data packet is transmitted after the voice packet transmission is completed when there is no silence part. Is decided.

When the voice / data arbitration means 13 determines the transmission order for transmission to the receiving device 20, the frame buffer means 14 temporarily stores voice packets and data packets (S106). Then, the transmitting means 15 takes out the voice packet or the data packet to be transmitted from the frame buffer means 14 according to the transmission order determined by the voice / data arbitrating means 13 and transmits it to the receiving device 20 (S107).

On the other hand, in the receiving device 20, as shown in the flowchart of FIG. 6, when voice packets or data packets are transmitted from the transmitting means 15 of the transmitting device 10, these voice packets or data packets are received by the receiving means 21. (S201). Then, the voice / data identification means 22 determines whether the reception means 21 receives a voice packet or a data packet.
Identification according to each packet type (S20
2). When the voice / data identifying unit 22 identifies the voice packet, the voice frame buffer unit 23 temporarily stores the voice packet (S20).
3).

When a voice packet corresponding to the voiced portion of the voice signal before division is accumulated in the voice frame buffer means 23, the voice signal reproducing means 24 judges whether or not there is a voice packet missing ( S204), if there is a missing voice packet, waveform replacement processing means 24a
The voice waveform is replaced by to complement the missing voice packet (S205). When there is no missing voice packet or when the replacement of the voice waveform by the waveform replacement processing means 24a is completed, the voice signal reproducing means 24 continues,
The audio signal before division is reproduced from the audio packets accumulated in the audio frame buffer means 23 (S206). However, here, only the sound part is reproduced according to the sequence number stored in the packet sequence number of the voice packet. Further, the silent part of the audio signal is reproduced according to the information indicating the time length of the silent part stored in the packet additional information of the audio packet. Then, the reproduced audio signal is output by the audio output unit 24b.

When the voice / data identifying means 22 identifies that the data packet is received by the receiving means 21, the data frame buffer means 25 temporarily stores the data packet (S20).
7). Then, when the data packet corresponding to the effective portion of the data signal before division is accumulated in the data frame buffer means 25, the data signal reproducing means 26 judges whether or not there is a missing data packet (S208), and the data packet is missing. If there is a lost data packet, the retransmission request processing means 26a requests retransmission of the lost data packet and complements the lost data packet (S209).
When there is no missing data packet or when the retransmission of the missing data packet is completed, the data signal reproducing means 27 subsequently reproduces the data signal before division from the data packets accumulated in the data frame buffer means 25. , To the external device 33 via the modem 28. (S
210).

As described above, in the wireless communication system according to the present embodiment, the voice packet processing means 11 of the transmitting device 10 converts voice packets from voiced portions of the voice signal, and the data packet processing means 12 transmits data packets from the voiced portion. Data packets are respectively generated, and these are received by the receiving device 20.
It is adapted to be reproduced by the receiving device 20 after being transmitted to. Therefore, only the voiced portion of the voice signal or the data-bearing portion of the data signal is packetized and transmitted to the receiving apparatus 20, and unnecessary information such as the voiceless portion of the voice signal or the data-less portion of the data signal is transmitted. And efficient transmission can be performed. Further, in the wireless communication system of the present embodiment, the transmission order is determined by the voice / data arbitration means 13 so that the data packets are transmitted during the silent portion of the voice signal. Therefore, the voice signal and the data signal can be efficiently transmitted.

Further, in the wireless communication system of this embodiment,
The voice packet is prioritized over the data packet by the priority processing determining unit 13a and the voice packet is transmitted from the transmitter 10 to the receiver 2.
It is sent to 0. Therefore, the transmission of the voice packet is not delayed by the transmission of the data packet, and the immediacy of the transmission of the voice signal can be secured, so that the occurrence of the communication failure during the call in the wireless access system can be prevented. You can

Further, in the radio communication system of this embodiment, the voice replacing means 24a replaces the voice waveform, so that voice packets are lost due to deterioration of the radio transmission path during radio communication. Even in this case, it is possible to perform waveform replacement from a voice packet around the missing voice packet and reproduce it as a voice signal. Therefore, it is not necessary to retransmit the voice packet from the transmitting device 10, and it is possible to secure the immediacy of the transmission of the voice signal and perform the wireless communication with good signal quality in the wireless access system.

In this embodiment, the transmitting apparatus 10 is the base station and the receiving apparatus 20 is the mobile station, and the base station transmits data to the mobile station. The same is applicable when transmitting to a station, that is, when the mobile station is a transmitter and the base station is a receiver. Further, in the present embodiment, the case where the number of the receiving device 20 is one has been described, but by storing the information for clarifying the receiving destination in the header part of the short packet transmitted from the transmitting device 10, the one transmitting device 10 is stored. It is possible to simultaneously perform transmission from a plurality of receiving devices 20. By thus transmitting information by utilizing the characteristics of packet communication, there is an advantage that wireless resources such as communication channels can be effectively used, as compared with conventional transmission based on circuit switching.

[0032]

As described above, in the wireless communication system of the present invention, the transmitter generates the voice packet from the voiced portion of the voice signal and the data packet from the data portion of the data signal. Is transmitted to the receiving device and then reproduced by this receiving device. Therefore, since only the voiced portion of the voice signal or the data present portion of the data signal is packetized and transmitted,
Efficient information transmission can be performed without transmitting unnecessary information. Further, since the transmission order of the voice packet and the data packet is determined by the voice / data arbitration means of the transmitter, the data packet can be transmitted, for example, during the silent portion of the voice signal. Therefore, it is possible to interrupt the data packet without waiting for the call release of the communication channel unlike the conventional circuit-switched transmission, and as a result, it is possible to efficiently transmit the voice signal and the data signal. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a wireless access system of a wireless communication system according to the present invention.

FIG. 2 is a block diagram showing the configuration of the entire system of the wireless communication system of FIG.

FIG. 3 is an explanatory diagram showing a structure of a voice packet (short packet).

FIG. 4 is an explanatory diagram of waveform replacement processing in the waveform replacement processing means.

5 is a flowchart showing an operation example of transmission in the wireless communication system of FIG.

FIG. 6 is a flowchart showing an operation example of reception in the wireless communication system of FIG.

FIG. 7 is an explanatory diagram showing a conventional transmission frame by circuit switching.

[Explanation of symbols]

10 transmitting device (base station) 11 voice packet processing means 12 data packet processing means 13 voice / data arbitration means 13a priority processing determining means 15 transmitting means 20 receiving device (mobile station) 21 receiving means 22 voice / data identifying means 24 voice signal Reproducing means 24a Waveform replacement processing means 26 Data signal reproducing means

Claims (3)

[Claims] 1. When a voice signal for a call and / or a data signal for data communication are input, a transmitting device that wirelessly transmits the input signal, and the voice from the transmitting device. A wireless communication system comprising a signal and a receiving device for receiving and outputting the data signal, wherein the transmitting device divides a voiced portion of the audio signal into predetermined units to generate an audio packet. Voice packet processing means, data packet processing means for dividing a data-existing portion of the data signal into a predetermined unit to generate a data packet, the voice packet generated by the voice packet processing means and the data packet processing means Voice / data arbitration means for determining the transmission order of each of the data packets generated in step 1, and the voice / data arbitration means. Transmitting means for transmitting the voice packet and the data packet to the receiving device according to a specified order, the receiving device receiving means for receiving the voice packet and the data packet from the transmitting means; A voice / data identification means for identifying whether the one received by the reception means is the voice packet or the data packet, and the voice signal is reproduced from the voice packet identified by the voice / data identification means. And a data signal reproducing means for reproducing the data signal from the data packet identified by the voice / data identifying means. 2. The voice / data arbitration means is provided with a priority process determination means for determining that the voice packet is transmitted with priority over the data packet. Wireless communication system. 3. The audio signal reproducing means includes a waveform replacement processing means for reproducing an audio signal based on the audio packets around the missing audio packet when the received audio packet is missing. The wireless communication system according to claim 1, wherein the wireless communication system is provided.