JP2008048453A - Reception device and reception method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmitting/receiving device, in particular a reception device, wherein the device configuration is simplified while the transmission efficiency of up/down frame is enhanced for efficient system management in a mobile communication system. <P>SOLUTION: The device comprises: a voice data generating part 31 that generates a voice frame in which voice data encoded for each prescribed cycle T1 are housed; a transmission frame generating part 32 that generates a plurality of transmission frames each of which has a prescribed cycle T2 longer than the prescribed cycle T1, and is assigned with a voice having the length of a super frame SF as voice data shorter than that acquired from the voice data generating part 31; and a super frame generating part 32 that arranges transmission frames having a prescribed cycle T3 of a length which is n times that of the prescribed cycle T2 and having 2 to (n-1) frames of voice data therein and transmits them. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transmission / reception apparatus for mobile communication, and more particularly to a base station and a reception apparatus and a reception method that constitute each mobile station in a mobile communication system using a digital modulation scheme.

  Various forms of mobile communication systems are currently in practical use. However, the system of the present invention described below mounts a mobile station on a car (such as a taxi) and a base station (such as a dispatch center). ) Illustrates a vehicle allocation system for grasping the position and dynamics of each mobile station (the state of an empty vehicle / actual vehicle / an incoming vehicle, etc.) and issuing a vehicle allocation instruction to each mobile station. More specifically, a GPS-AVM (Grobal Positioning System-Automatic Vehicle Monitoring) system will be described as an example. In this GPS-AVM system, a mobile station autonomously grasps its own position using GPS, and further notifies the dispatch center of the position data by itself. The current dispatch system is the GPS-AVM system. The system is becoming mainstream.

FIG. 22 is a diagram showing a typical frame configuration example in a mobile communication system using a digital modulation scheme.
In this figure, column (1) shows the frame configuration of the downlink frame from the base station to the mobile station, and column (2) shows the frame configuration of the uplink frame from the mobile station to the base station.
This figure shows an arbitrary part (near No. N) in the frame flow. As shown in the figure, in a general frame flow, time is divided into frame units. Then, encoded audio data and non-audio data are transmitted by each divided frame. In this case, the attribute of whether it is audio data or non-audio data is determined by control data arranged at a predetermined position in each frame. In a general mobile communication system, communication is performed according to the frame flow as described above.

FIG. 23 is a diagram showing a schematic configuration of a GPS-AVM system, which is one form of the general mobile communication system. As described above, the present invention will be described taking the GPS-AVM system as an example.
In this figure, reference numeral 1 is, for example, a GPS-AVM system that forms a dispatch system, and a plurality of base stations 2 that form a dispatch center and a plurality of base stations 1 that are mounted on a car (such as a taxi) and communicate wirelessly. Mobile station (1 to n) 3.

Transmission is performed from the base station 2 by the half duplex method at the frequency f2. That is, even when there is no data to be transmitted, some data is always arranged in each frame for transmission. On the other hand, the mobile station 3 can grasp the timing of each frame.
The mobile station 3 transmits at the frequency f1, but whenever there is data to be transmitted to the base station 2, the data is transmitted in accordance with the timing of each frame. The mobile station 3 transmits necessary data to the base station 2 in accordance with the timing of each frame only when designated by the base station 2.

  In particular, in the GPS-AVM system 1, an uplink frame is frequently transmitted to the base station 2 so that the current position and dynamics (actual vehicle / empty vehicle / passing vehicle) of each of a large number of mobile stations 3 can always be accurately grasped. . For this reason, an arbitrary transmission method is adopted for the current position. In this method, every time the mobile station 3 moves a certain distance such as 50 m, the base station 2 is notified of the position autonomously using an uplink frame.

Each configuration of the base station 2 and the mobile station 3 is as follows.
FIG. 24 is a diagram illustrating a configuration example of a mobile station side transmission / reception device in the GPS-AVM system.
In this figure, the transmitter / receiver 4 of the mobile station 3 performs only a reception operation at the time of reception and only a transmission operation at the time of transmission.

A signal from the base station 2 is received by the transmission / reception unit 9 via the base station communication antenna. Further, after demodulating the received signal by the digital modulator / demodulator 8, the control unit 7 reproduces the contents. If it is now determined that the content is audio data, the bit string is decoded by the audio decoder 6 and output from the speaker as the original audio.
When it is determined that the dispatch data is for the own station, this is displayed on the data display unit 10.

  On the other hand, when transmitting voice from the mobile station 3 to the base station 2, the operator pushes the transmission switch (ON) and inputs it from the microphone. This input speech is encoded by the speech encoder 5 and converted into a bit string. The control unit 7 receives this, adds a code indicating that it is voice, and sends it to the digital modulator / demodulator 8. Here, the signal is modulated into a predetermined format and transmitted from the antenna.

On the other hand, the position data of the mobile station 3 is generated by the GPS receiver 11 by receiving a GPS signal from a GPS satellite. The control unit 7 transmits the position data every time it is more than a certain linear distance from the previous position data transmission.
On the other hand, the configuration on the base station side is as follows.
FIG. 25 is a diagram illustrating a configuration example of the base station side transmitting / receiving device 12 in the GPS-AVM system.

In the transmission / reception apparatus 12 in this figure, when the transmission switch is pressed by the operator and voice is input from the microphone, the signal is modulated by the digital modulator 15 and transmitted from the transmission unit 16 to the mobile station 3 via the antenna. As sent.
The dispatch data from the base station 2 is inputted by the operator by operating the client 18, and the host computer 17 that receives the data sends the mobile station through the transmission control unit 14 as in the case of the input voice. Send to 3 side.

  On the other hand, when the position data of each mobile station transmitted from the mobile station 3 side by the above-described arbitrary transmission method is received via the antenna by the receiving unit 22, the digital demodulator 21 demodulates the original position data. When the reception control unit 20 determines that this is not voice information but position information, it is input to the host computer 17 side and further sent to the client 18.

On the other hand, when it is determined by the above demodulation that the above-mentioned audio information is obtained, the original audio is reproduced by the audio decoder 19 and output from the speaker to the operator.
The subject of the present invention particularly relates to the frame shown in FIG.
FIG. 26 is a diagram showing a frame configuration example according to the first conventional example. This first conventional example is based on Japanese Patent Application No. 2000-035672 (Japanese Patent Laid-Open No. 2001-223630) by the present applicant. Here, for the sake of simplification, description of bits such as a synchronization signal, error correction bits, rising and falling ramp times, and guard times necessary for the digital modulation method is omitted.

In addition, here, it is assumed that the transmission amount is 40 mS, and the transmission amount obtained by removing the above-mentioned omitted bits from the total transmission amount 9600 BPS. Therefore, the transmission amount of one frame (including the error detection code) ) Is 169 bits. In the following, description will be made with the 169 bits unified.
In FIG.
M is a bit indicating the number of the destination mobile station 3 in the downstream frame and the number of the source mobile station 3 in the upstream frame.
D / V is a bit for distinguishing whether the subsequent voice / non-voice data portion is voice data or non-voice data,
The voice / non-voice data contains each content of voice data or non-voice data.

  With regard to this audio data, an example is shown in which the AMBE method (AMBE: Advanced MultiBand Excite (DVSI, USA)), which is currently considered to have the highest compression rate among the audio encoding methods, is employed. According to this AMBE method, sound is processed with a sound frame every 20 mS as one unit, and 48-bit compressed sound data is generated per unit. In FIG. 26, audio data is generated and assigned in 96 bits as an audio signal for 40 mS (2 × 20 mS) by the AMBE method.

The control data (46 bits) following the 96 bits is a response signal to the transmission signal by the above arbitrary transmission method in the upstream frame.
The CRC (16 bits) following this control data is an error detection code for discarding the data when an error during transmission is detected. In FIG. 26, the elongated portion c indicates that the CRC calculation is applied to M, D / V, voice / non-voice data, and control data. In other words, CRC is added to detect bit errors from all these bit ranges.

  For example, in the GPS-AVM system applied to a taxi dispatch system, the non-speech data includes the dispatch data (usually a plurality of frames), the response signal (single frame), etc. On the other hand, the uplink non-voice data contains position data (single frame), dynamic data (single frame), etc. of the mobile station 3, respectively.

According to the first conventional example described with reference to FIG. 26, although the frame can be applied to the downlink transmission signal, it cannot be applied to the uplink transmission signal. Consequently, the transmission efficiency of the uplink communication is improved. There is an inconvenience that it cannot be made.
There is a second conventional example by the present applicant that can avoid this inconvenience. This is Japanese Patent Application No. 11-214275 (Japanese Patent Laid-Open No. 2001-44920). Here, a transmission frame of another period is created by compressing the audio frame. By using this new transmission frame, even when a certain mobile station transmits an uplink signal, other mobile stations can transmit the uplink signal data. The following are known examples related to the present invention.
International Publication No. 00/56108 Pamphlet

  In the second conventional example, in the first aspect, it is proposed to change the frame length between the upstream frame and the downstream frame. For example, (i) 20 mS reception and 20 mS transmission, and (ii) 30 mS reception and 30 mS transmission.

However, if it does so, the program in the case of (i) and the program in the case of (ii) are required, and there is a first problem that the processing becomes complicated.
In addition, since the base station 2 and each mobile station 3 must maintain different programs, there is a second problem that an economical system cannot be constructed.
Furthermore, there is a third problem that the transmission timing of the mobile station 3 must be synchronized in units of a plurality of frames transmitted by the base station 2, and the transmission timing setting means becomes complicated. .

Even if another aspect other than the first aspect of the second conventional example is adopted, the transmission timing of the transmission frame is a plurality of frames of the audio frame because the audio frame length and the transmission (non-audio) frame length are different. Synchronization must be performed in units, and the same problem as the third problem occurs.
Therefore, in view of the above problems, the present invention aims to provide a transmitting / receiving apparatus for mobile communication, particularly its receiving apparatus and its receiving method, which can greatly improve the operation efficiency of the system. is there.

Specifically, in a mobile communication system such as a GPS-AVM system, it is easy to take transmission timing. Therefore, it is possible to reduce the cost by simplifying the configuration of the transmission / reception device, and not only the downlink frame but also the uplink frame. The purpose of this is to improve the signal transmission efficiency.
Another object of the present invention is to enable efficient communication not only between the base station and each mobile station but also between the mobile station and the mobile station.

FIG. 1 is a diagram showing a basic configuration example of a transmission / reception apparatus according to the present invention.
The configuration of the transmitting / receiving apparatus according to the present invention is substantially the same for each mobile station apparatus (4) and base station apparatus (12).
The transmission / reception devices 4 and 12 have superframe sending means 30. The super frame sending means 30 stores data (IN) to be transmitted to the receiving side by dividing it into a plurality of frames each having the same time length, and assembles a series of frames into a super frame and transmits (OUT). .

As an example, the super frame sending means 30 can be composed of an audio data generating unit 31, a transmission frame generating unit 32, and a super frame generating unit 33 as shown in the lower part of FIG. These generation units will be described in detail later.
FIG. 2 is a diagram showing a frame configuration example output from the superframe sending means 30.

  That is, the output OUT in FIG. 1 forms a super frame SF, and is composed of a plurality of frames fr each having the same time length (for example, 40 mS), and is 160 mS as a whole. In the figure, four frames fr (0 to 3) are shown as an example. That is, the super frame SF is assembled using 4 frames as a unit of repetition. Then, audio data and non-audio data are distributed in a super frame SF including four frames fr having the same frame length.

One feature of the present invention is that in the second conventional example, the frame lengths of the upstream frame and the downstream frame are different from each other, but all have a common frame structure.
The following points are also one of the features of the present invention. That is, one is a mobile communication transceiver device 12 provided in the base station 2, and the other is a mobile communication transceiver device 4 provided in each of the plurality of mobile stations 3, from the base station 2 to the mobile station 3. The downlink superframe SF (downlink) to the mobile station 3 and the uplink superframe SF (uplink) from the mobile station 3 to the base station 2 are both configured in the same frame configuration.

Thus, the first, second and third problems described above are basically solved.
In this case, the above-described feature that a plurality of the same frames fr are assembled into a super frame SF seems to be similar to the TDMA technology used in a general digital mobile phone. However, this TDMA technique is different. This point will be described later.

  As will be described later, according to the present invention, a new transmission method that is not available in the conventional mobile communication system is realized, and by this transmission method, the base station constituting the system and the hardware of the transmitting / receiving device of each mobile station are implemented. Hardware configuration and software can be greatly simplified. Therefore, the economics of the system is greatly improved. In addition, the transmission efficiency of both the downstream frame and the upstream frame is increased, and the operation efficiency of the system is improved as compared with the conventional case.

  In addition, this transmission method can be applied to communication between mobile stations, and by inserting an unmodulated carrier into a specific frame, practical communication between mobile stations can be easily realized.

FIG. 3 is a diagram specifically showing the configuration of each frame fr shown in FIG. Throughout the drawings, similar components are denoted by the same reference numerals or symbols.
In FIG. 3, three frames 0 to 2 in FIG. 2 are shown in the column (1) as fr0 to fr2, and frame 3 in FIG. 2 is shown in the column (2) as fr3. In this figure, “M” (mobile station number), “voice data”, “CRC”, and “c” are the same as those described in FIG. Non-voice data is indicated as “transmission / control data”. The “accompanying data” can be used in a downstream frame when a simple instruction is given to the taxi crew. In addition, the uplink frame can be used for the dynamic notification described above.

The “frame No.” is one of the features of the present invention. In the transmission frame generation unit (31 in FIG. 1), a plurality of frames including a voice transmission frame fr0 to fr2 and a non-voice transmission frame fr3 are included. This is a unique frame number assigned to each transmission frame.
What should be noted in the frame configuration of FIG. 3 is that audio data obtained by encoding audio (160 mS) for four frames (fr0 to fr3) is compressed into three frames fr0 to fr2. That is.

As a result, a voice data transmission vacancy is created in the final frame fr3, and transmission / control data that is non-voice data can be accommodated in this vacant area.
Further, looking at the bit arrangement in each frame fr, in FIG. 3, “frame No.” is 2 bits for distinguishing the four frames, and “M” is about 1000 taxis (mobile stations). ) Is 10 bits sufficient to identify the data, “accompanying data” is 13 bits sufficient to notify various information related to the above-described dynamics, and “CRC” is 16 bits as in FIG.

  Looking at “voice data”, as described above, the voice of 160 mS is equally distributed to the three frames fr0 to fr2, so each voice data corresponds to a voice of 53.333 (= 160/3) mS. Further, as described above, in the AMBE system, 20 mS sound is converted into 48-bit sound data. Therefore, the sound data (53.333 mS) in FIG. 3 becomes 128 (= 48 × 160/20) bits, and the frames fr0 to fr0. As described above, each fr2 is unified to 169 bits as a whole. Since the frame fr3 is also 169 bits as a whole, 141 bits are assigned to the transmission / control data.

  With the frame structure as shown in FIG. 3, audio data and transmission / control data are superimposed and transmitted in the downstream frame. In the uplink frame, when voice is transmitted from a certain mobile station 3, the voice data is not transmitted in the frame fr3 in the super frame SF transmitted from the mobile station. Therefore, non-voice data (transmission data) can be transmitted to the base station 2 in the frame fr3. In addition, since the upstream frame and the downstream frame have the same frame period of 40 mS, the device configurations of the transmission / reception devices 4 and 12 are simplified.

Reference is now made to FIG. 3 and the lower part of FIG. The three generating units 31, 32 and 33 of FIG. 1 constituting the superframe sending means 30 operate as follows.
The audio data generation unit 31 generates audio to be transmitted to the receiving side as an audio frame that accommodates audio data encoded every first predetermined period T1 (corresponding to 20 mS described above).

  The transmission frame generation unit 32 is a plurality of transmission frames each having a second predetermined period T2 (corresponding to the aforementioned 40 mS) longer than the first predetermined period T1, and has a time length (160 mS) of the superframe SF. Corresponding voices generate a plurality of transmission frames (fr0 to fr3) allocated as voice data (128 bits) of a shorter time obtained from the voice data generation unit 31.

The superframe generator 33 is a superframe SF having a third predetermined period T3 (160 mS) that is n times (for example, n = 4) times the second predetermined period T2, and the audio data is 2 or more and (N-1) The following transmission frames (3 transmission frames in FIG. 3) are arranged in the SF and transmitted.
Here, the reason why it is expressed as “a transmission frame of 2 or more and (n−1) or less” will be described while clarifying the difference from the TDMA technique described above.

  As described above, the present invention is similar to the TDMA technology used in the digital cellular phone, but the TDMA technology uses a wide band to increase the transmission amount, and the transmission is divided into N by time accordingly. This is a method for constructing a road. Therefore, for a voice frame, a transmission slot having a length of 1 / N and a unit in which N transmission slots are collected is called a frame.

  On the other hand, the present invention has a limited bandwidth (narrow band), and the transmission amount per carrier (f1 and f2 in FIG. 23) is close to the transmission amount when a voice is encoded and a control signal is added. In some cases, a more efficient transmission scheme is provided. In this respect, it is essentially different from TDMA technology. In order to clarify this point in the superframe generation unit 33, the expression “a transmission frame of 2 or more and (n−1) or less” is used.

Next, an example of the operation in the transmission / reception devices 4 and 12 according to the present invention will be described.
FIG. 4 is a flowchart showing an operation example of the base station side transmitting / receiving apparatus 12.
First, the points of operation will be described. This also applies to other flowcharts described later.
In the present invention, since there is an emphasis on an air format for executing efficient transmission and control, only a flowchart for generating a transmission signal is shown, and a flowchart for reception is omitted. These flowcharts are executed for each frame as interrupt processing for each frame. Note that frame No. The initial value of (frame No.) is 0.

  In the operation example of the base station 2 shown in FIGS. 1 and 3, the frame number is set irrespective of the ON / OFF of the transmission switch. 0 to 2 (fr0 to fr2), the voice is frame No. In 3 (fr3), transmission data or control data is transmitted. Frame No. Is managed by the base station 2 and circulates through 0 → 1 → 2 → 3 → 0 →... To form a superframe SF.

On the receiving side, frame No. To distinguish between voice and data and proceed.
In the mobile station 3, the frame No. Is a frame number transmitted from the base station 2. The frame correspondence of the downlink frame / uplink frame and the uplink transmission timing are separately defined. Therefore, the transmission frame No. Is generated from the received data. For example, the frame No. of the upstream frame to be transmitted. 0, 1... Are the frame numbers of the received downstream frames. It is generated from 0, 1... With a predetermined fixed time delay.

  That is, when a superframe SF in which a unique frame number (frame No.) is assigned to each of a plurality of transmission frames including a transmission frame for voice and a transmission frame for non-voice is received from the transmission side, the received superframe is received. The transmission frame for transmission is sequentially generated in synchronization with the frame number in the SF and transmitted from the super frame generation unit 33.

In the mobile station 3, the frame No. If the transmission switch is pressed in the case of 0-2, the voice signal is sent to the frame number. In the case of 3, the position data is transmitted when a specified transmission condition such as traveling a certain distance from the previous position data transmission is satisfied.
Please refer to FIG.
Step S101: It is determined whether it is the transmission timing of the frame fr3.

Step S102: If YES, the data from the host computer 17 (FIG. 25) is set in the “transmission / control data” bit (FIG. 3).
Step S103: If NO, the audio data from the audio encoder 13 is set in the “audio data” bit (FIG. 3).
Step S104: The accompanying data from the host computer 17 is set in the “accompanying data” bit (FIG. 3).

Step S105: The number of the destination mobile station 3 designated by the host computer 17 is set in M.
Step S106: frame No. Set.
Step S107: CRC is calculated and set to the CRC bit.
Step S108: One frame (fr0) is transmitted to the mobile station 3 side.

Step S109: The frame number (frame No.) is updated.
FIG. 5 is a flowchart showing an operation example of the mobile station side transmitting / receiving apparatus 4.
Step S201: equivalent to S101.
Step S202: If YES, it is determined whether or not the position data transmission conditions (such as whether the vehicle has traveled a certain distance since the previous position data transmission) are met.

Step S203: If YES, the position data at that time is set in the “transmission / control data” bit (FIG. 3).
Step S204: It is determined whether the transmission switch (FIG. 24) is pressed by the operator.
Step S205: If YES, the audio data from the audio encoder 5 (FIG. 24) is set in the “audio data” bit (FIG. 3).

Step S206: The accompanying data (empty vehicle / actual vehicle / receiving vehicle) is set in the “accompanying data” bit (FIG. 3).
Step S207: equivalent to S105.
Step S208: equivalent to S106.
Step S209: equivalent to S107.

Step S210: Corresponds to step S108. Thereafter, frame No. Update.
Having described the basic form of the present invention, various examples will be described below.
[First embodiment]
Under the first embodiment, the superframe sending means 30 sends non-voice data instead of voice data when there is no voice to be transmitted to the receiving side.

In the basic form of the present invention described above, even when there is no audio signal to be transmitted to the mobile station 3 side in the base station 2, audio data corresponding to silence is transmitted, and the use efficiency of radio waves is poor.
Therefore, in the first embodiment, when there is no audio data to be transmitted by the frames fr0 to fr2 in FIG. 3, fr0 to fr2 are provided instead for transmitting non-audio data.

FIG. 6 is a diagram showing a frame configuration example based on the first embodiment.
The column (1) in this figure is the frames fr0 to fr2 as described above, but when there is no audio data, non-voice data similar to the frame fr3 in the column (2) is transmitted as fr0 to fr2.
Therefore, it is preferable to include a 1-bit D / V bit indicating whether audio data or non-audio data, and in the case of non-audio data, for example, a 6-bit frame for indicating the type of the data. Preferably it contains attribute bits.

As described above, the transmission frame generation unit 32 generates non-voice data to be transmitted to the reception side together with the voice data in addition to the voice transmission frame for sending the voice data. The frame SF can be inserted as at least one non-voice transmission frame.
The transmission frame can further include frame attribute bits indicating what kind of data the non-voice transmission frame contains.

It should be noted that additional data (accompanying data and M bits) that can be distinguished from audio and non-speech information can be included in the audio transmission frame as 6-bit “accompanying data” shown in FIG.
FIG. 7 is a flowchart showing an operation example of the base station side transmitting / receiving apparatus 12 under the first embodiment,
FIG. 8 is a flowchart showing an operation example of the mobile station side transmitting / receiving apparatus 4 under the first embodiment.

First, the points of operation in the first embodiment will be described.
In the first embodiment, in order to distinguish between non-voice data and voice data, one D / V bit described above is arranged, where 0 = voice and 1 = non-voice.
In particular, in the case of non-speech data, 6 bits of the above-described frame attribute bits are arranged to indicate what kind of data the data is. In this example, 000000 = no designation (because it is voice or the like, no attribute is designated), 000001 = notification signal (information for simultaneously broadcasting operation parameters etc. from the base station 2 to the mobile station 3), 000010 = control signal, 000100 = Position signal (upstream frame).

  The frame number of the downstream frame. 0 to 2 can be used in a variety of ways, such as when the frame is used for transmission of general information, when used for the notification signal, and when used for control or the like when there is no audio transmission. However, for simplification of explanation, only the notification signal is shown in this example. Further, on the mobile station side, the transmission frame of the position data is designated as frame No. 3 (fr3) only, and the operation example was simplified.

With such a configuration, the use efficiency of radio waves for the downstream frame is greatly improved.
Reference is now made to FIG.
Step S301: equivalent to S101.
Step S302: equivalent to S102.

Step S303: To transmit transmission / control data, the D / V bit is set to 1, that is, non-voice data.
Step S304: The illustrated bit pattern indicating control data is set in the 6 frame attribute bits.
Step S305: If the result of step S301 is NO, it is determined whether the transmission switch (FIG. 25) is pressed.

Step S306: If NO, this step is reached. This corresponds to step S102.
Step S307: Corresponds to step S303.
Step S308: In this example, since the notification signal is transmitted, the bit pattern shown in the figure is set for the 6 frame attribute bits.

Step S309: If the result of step S305 is YES, the data from the speech encoder 13 (FIG. 25) is set to the “speech data” bit.
Step S310: The accompanying data from the host computer 17 (FIG. 25) is set in the “associated data” bit.
Step S311: 0 indicating the voice is set in the D / V bit.

Step S312: In this case, since it is audio data, a 6-bit 0 pattern is set.
Steps S313 to S317 correspond to S105 to S109, respectively.
Next, referring to FIG.
Steps S401 to S414 mostly correspond to steps S201 to S210 in FIG.

The different steps are steps S404, S405, S409 and S410, which correspond to steps S303, S304, S311 and S312 of FIG.
[Second Embodiment]
Basically, the second embodiment generates non-voice data to be transmitted to the receiving side together with voice data in addition to the voice transmission frame for sending voice data, and at least one non-voice data is included in the superframe SF. The transmission frame is inserted as a voice transmission frame, and the transmission efficiency can be further increased.

FIG. 9 is a diagram showing a frame configuration example based on the second embodiment.
In this figure, columns (1) to (3) are frames fr0 to fr2 for audio data, and column (4) is a frame fr3 for non-audio data.
In the frame configuration shown in FIG. 3, additional data such as accompanying data and M bits are individually included in each audio transmission frame.

  However, in the frame configuration shown in FIG. 9, additional data such as accompanying data that should be individually included in each audio transmission frame is grouped into one of the super audio transmission frames, for example, the first audio transmission frame. It is included. That is, in the example described above, the M bits and the accompanying data individually included in the frames fr1 and fr2 are collectively accommodated in the first frame fr0. This is because the fr0 to fr2 (fr3) are grouped in one superframe SF and are not separated from each other.

  Referring to FIG. 9, the accompanying data is 38 bits. This is 38 (= 18 + 20) bits, in which the associated data of 6 bits each is originally grouped into three (18 bits), and further M bits (20 bits) of the frames fr1 and fr2 of 10 bits are aggregated. By using these 38 bits, it is possible to superimpose a more detailed vehicle dispatch instruction while transmitting voice on the downlink, or to superimpose position data on the voice almost in real time on the uplink.

  Further, according to the frame configuration of FIG. 9, the following advantages can be produced. As described above, each frame is standardized to 169 bits. However, if the bit arrangement as shown in the figure is used, the basic voice data 1 to 8 corresponding to just eight pieces are divided into three voice frames (fr0 to fr2) as shown in the figure. It can be embedded without any gaps. That is, each basic audio data can be embedded in a frame in the form of a basic audio unit obtained by converting 20 mS of audio into 48-bit audio data based on the AMBE method described above.

As a result, the processing in the apparatus can be further simplified.
FIG. 10 is a flowchart (part 1) showing an operation example of the base station side transmitting / receiving apparatus 12 under the second embodiment.
FIG. 11 is the same flowchart (No. 2).
FIG. 12 is a flowchart (part 1) showing an operation example of the mobile station side transmitting / receiving apparatus 4 under the second embodiment.
FIG. 13 is the same flowchart (No. 2).

  Since most of the flowcharts here are the same as the previous flowcharts, only the steps that differ from the previous flowcharts will be particularly described. In the flow charts of FIGS. 11 to 14, from the viewpoint of the second embodiment, in order to prevent the transmission of audio frames of 2 frames or less, the audio transmission start is always set to the frame fr0 including the above-described additional bits, and the audio transmission is performed. The end frame is a frame fr2. Note that the initial value of the transmission state flag is OFF. This transmission state flag corresponds to a bit of a register (not shown) that stores that the transmission switch is not pressed or has not been pressed.

First, referring to FIGS. 10 and 11, in step S10, it is determined whether the transmission frame is the start frame fr0 and the transmission switch (FIG. 25) is ON.
In step S11, it is determined whether the transmission frame is the end frame fr2 and the transmission switch is OFF.

Steps S12 and S13 are reached when the results of the previous steps S10 and S11 are YES.
Step S14 is reached when both the results of steps S10 and S11 described above are NO, and the speech processing process and the non-speech processing process are entered according to YES and NO of the result of step S14, respectively.

Next, referring to FIG. 12 and FIG. 13, steps S20 to S24 are new steps, which correspond to the above-described steps S10 to S14, respectively.
[Third embodiment]
FIG. 14 is a diagram showing a frame configuration example based on the third embodiment.
In the third embodiment, an error detection code CRC is added to the non-voice transmission frame (fr3), and the portions other than the voice data (D / V, M, accompanying) in the voice transmission frames (fr0 to fr2). The error detection code CRC is added to the data or the like. In other words, the audio data portion is excluded from the CRC application range. That is, the application range c of the error detection code CRC shown in FIG. 3 and the like is narrowed as shown by c1 in FIG. The reason for this and the advantages of this are as follows.

In audio transmission, when an error is detected in a bit in a received frame on the receiving side, the data of the frame is discarded, and instead the data of the previously received frame is filled and sent to the audio decoder (6, 19). This is often done. This is a so-called bad frame masking process.
However, actually, even if a certain amount of error is included in the audio data and sent to the audio decoder, there is no fatal deterioration in hearing. ... (i)
On the other hand, when the error detection code CRC has the same detection code length (16 bits in FIG. 14), if the length of data to be detected (c1 and c in FIG. 14) becomes longer, there is a probability that an error cannot be detected. Get higher. ... (ii)
From the above two facts (i) and (ii), the structure of the frame for transmitting the voice is excluded as shown in FIG. 14, and the voice data is excluded from the application range of the CRC to be error-detected. As a result, the probability that error detection cannot be performed in signals other than voice (non-voice data) can be reduced, and the reliability of the GPS-AVM system can be improved.

FIG. 15 is a flowchart showing the characteristics of the third embodiment.
However, this figure shows a part of the flowchart of FIG. However, the other flowcharts described above are similarly applied to the portion for executing the CRC calculation.
Step S31 in FIG. 15 is a characteristic part of the third embodiment. Here, the CRC calculation application range of the non-voice data bits is specified.
[Fourth embodiment]
FIG. 16 is a diagram showing a frame configuration example based on the fourth embodiment.

  In the fourth embodiment, an error detection code CRC is added to a voice transmission frame (fr0 to fr2), an error detection code CRC is added to a non-voice transmission frame (fr3), and each transmission frame is added. The data format of the data to which the corresponding error detection code is applied is unified for all transmission frames. The reasons for this and the advantages of this are as follows.

  In the frame configuration of FIG. 14 (third embodiment), there are three types of error detection bit configurations: <1> audio frames fr0, <2> audio frames fr1 and fr2, and <3> non-audio frames fr3. I can do it. For this reason, in the mobile station 3, the frame No. When it is not known, it is necessary to try to detect an error with the three types of formats applied to the above <1> to <3>.

As a result, the operation of the apparatus becomes complicated. Also, frame No. However, since the bit structure is different between the audio frame and the non-audio frame, it is necessary to detect errors in two types of formats.
In order to eliminate such inconvenience, the frame configuration is configured as shown in FIG. As a result, the error detection bit configuration common to all frames (fr0 to fr3) can be made (see cc in the figure, all 57 bits). This leads to simplification of the device.

  By adopting such a configuration, when an error is detected in the bits up to the first CRC and it is determined that there is no error, the frame No. And D / V can be processed according to their bit configurations. Even if an error is detected in the bits up to the first CRC, the frame No. of the immediately preceding frame is detected. Is already known, the frame No. of the frame immediately after that is determined. Therefore, there is a high possibility that the speech data contains an error, but even if it is sent to the speech decoder as it is, there is no great inconvenience.

  In order to realize the unification of the data format for CRC as described above, one contrivance is added in the fourth embodiment. That is, by adding a part of audio data to the data to which the error detection code CRC is applied in the audio transmission frames (fr1 and fr2), the data format of the audio transmission frame is set to non-audio. The data format is unified with the data format of the transmission frame fr3. Specifically, the part of the audio data added as described above is the audio data 3 and the audio data 6 in the columns (2) and (3) of FIG.

  In this way, in the audio frames fr1 and fr2, there is a demerit that the error detection capability is certainly reduced by the addition of the audio data 3 and 6. On the other hand, the benefits of unifying the format into one type are much greater. For example, there is a merit that software in the apparatus can be simplified. Further, regarding the non-voice frame fr3, error detection can be detected by dividing it into two blocks (see cc and cc 'in the column (4) in FIG. 16), so that the error detection capability can be further enhanced.

The flowchart based on the fourth embodiment is exactly the same as the above-described flowcharts, and will be omitted. However, the flowchart shown in FIG. 15, in particular step S31 is unnecessary. This is because the calculation range in step S31 is constant as described above.
In the present invention, the audio frames fr0 to fr2 and the non-voice (control) frame fr3 shown in FIG. 3 are set as one set to form a super frame SF, and this SF is continuously transmitted. If such a configuration is skillfully used, the following application examples are possible.
[Fifth embodiment]
FIG. 17 is a transmission frame configuration diagram for explaining the fifth embodiment.

  The column (1) in this figure is common to the basic form described above and the first to fourth embodiments, and represents an actual transmission frame. In the column (1), the field indicated as “signal body” corresponds to the frames fr0 to fr3 described so far. However, in an actual transmission frame, the rising and falling ramp times RAMP1 and RAMP2, the synchronization signal SYNC, and the guard time GUARD, which are indispensable for digital modulation, are arranged with the number of bits shown in the figure. The “signal body” is arranged with 348 bits. As described at the beginning, all the frames are described as being unified to 169 bits, but actually, a bit string that is error-correction-coded is added to the 169 bits and transmitted. This is a 348-bit signal body.

Next, referring to the column (2) in FIG. 17, this is a transmission frame used in the fifth embodiment, specifically, a transmission frame based on the above-described non-voice frame fr3.
The fifth embodiment is characterized in that, in a super frame SF generated by modulating a carrier, one transmission frame in the super frame SF is an unmodulated carrier. A transmission frame carrying an unmodulated carrier is a non-voice transmission frame (fr3).

The background of the fifth embodiment to which the present invention is applied is as follows.
In a GPS-AVM system or the like, there is a case where a call is made between mobile stations. For example, it may be necessary to communicate with a nearby mobile station when the base station is out of the coverage area.
In communication between the base station 2 and the mobile station 3, in the case of a half-duplex system in which the base station 2 keeps transmitting, the mobile station automatically performs frequency control on the frequency of the base station. What is necessary is just to follow the frequency. At this time, since the base station is a fixed station, its transmission frequency accuracy is generally set high.

However, in the mobile station, the frequency deviation is generally set to be loose from the viewpoint of cost and space. For this reason, when a call is made between a mobile station and a mobile station as described above, the frequency deviation between the mobile stations becomes even larger, and the reception performance may deteriorate or sometimes reception may not be possible.
In addition, since the mobile station suddenly transmits a frame only when the local station transmits, the other mobile station performs automatic control at high speed to match the transmission frequency at the start of the call, and within a short time There arises a problem that the reception frequency of the local station must be followed.

As a solution to this problem, in the fifth embodiment, attention is paid to the frame fr3 in which a voice transmission vacancy occurs in the super frame configuration of the above-described embodiments, and a carrier that does not apply digital modulation to this frame, that is, no modulation. Insert a carrier and send it to the other mobile station. The reason for the unmodulated carrier is clear from FIG.
FIG. 18 is a spectrum diagram for explaining the fifth embodiment.

This figure shows a non-modulated carrier and a modulated carrier digitally modulated with audio data / non-audio data. As is apparent from the figure, the spectrum of the modulated carrier is wide. On the other hand, the spectrum of the unmodulated carrier is very narrow.
Therefore, the receiving-side mobile station can pull in the frequency much faster by receiving an unmodulated carrier having a narrow spectrum than a modulated carrier having a broad spectrum that is difficult to follow the frequency.

Thus, if the transmitting-side mobile station outputs the unmodulated carrier in FIG. 18 at the timing of the frame fr3 in the superframe SF, the receiving-side mobile station uses the unmodulated carrier in the received frame fr3 at a high speed. The frequency can be pulled in with.
More preferably, the non-voice transmission frame (frame fr3) carrying the unmodulated carrier is arranged at the head in the super frame SF. Thereby, the starting timing of the frequency control circuit can be further advanced.

FIG. 19 is a flowchart (part 1) showing an operation example of the mobile station side transceiver 4 based on the fifth embodiment,
FIG. 20 is the same flowchart (No. 2).
Most of the flowcharts shown in FIGS. 19 and 20 are almost the same as the above-described flowcharts. The difference is steps S41 and S42 unique to the present embodiment.

In step S41, when it is determined in the preceding step that the frame is fr3, it is determined whether a call between the mobile stations is started and whether the transmission switch (FIG. 24) is pressed.
In step S42, when the determination result is YES, the above-mentioned unmodulated carrier is inserted into the frame fr3 and transmitted to the receiving-side mobile station for one frame. Thereafter, several frames are transmitted, and when a response signal is returned from the receiving mobile station, a frame fr3 carrying normal control data is transmitted instead of the unmodulated carrier.

With the above configuration, it is easy to cause the other station to follow at high speed even in a call between mobile stations.
[Sixth embodiment]
Finally, the sixth embodiment will be described. The sixth embodiment is an improvement over the above-described fifth embodiment with respect to synchronization protection.

FIG. 21 is a transmission frame configuration diagram for explaining the sixth embodiment.
In this figure, the synchronization signal SYNC which is not seen in FIG. 17 (fifth embodiment) is incorporated. That is, the sixth embodiment is characterized in that the synchronization signal SYNC (20 bits) is included at the head of the unmodulated carrier portion (368 bits).

The background for which the sixth embodiment is required will be described next.
In general, when receiving a continuous signal having a frame structure, the timing of the synchronization symbol of the currently received frame is confirmed from the timing of the synchronization symbol of the previously received frame. If the timing of the synchronization symbol cannot be confirmed due to fading or the like, synchronization protection is performed by estimating the synchronization symbol from the previous frame and demodulating the synchronization symbol (see, for example, Japanese Patent Laid-Open No. 7-162473: Digital communication synchronization protection method). ).

However, in the method of the fifth embodiment described above, there is no synchronization signal when receiving an unmodulated carrier, and synchronization protection cannot be applied. That is, since the synchronization protection is skipped once every four frames at the frame fr3, the forward protection is weakened.
In order to solve this, an unmodulated carrier is transmitted after the synchronization symbols are arranged. FIG. 21 shows the structure of this frame.

  As a result, it is possible to ensure synchronization protection when sending an unmodulated carrier even in a call between mobile stations.

It is a figure which shows the basic structural example of the transmission / reception apparatus which concerns on this invention. FIG. 4 is a diagram showing an example of the configuration of a frame output from a super frame sending means 30. FIG. 3 is a diagram specifically showing the configuration of each frame fr shown in FIG. 2. 5 is a flowchart illustrating an operation example of a base station side transmitting / receiving device 12; 4 is a flowchart showing an operation example of a mobile station side transmitting / receiving apparatus 4. It is a figure which shows the example of a frame structure based on 1st Example. It is a flowchart which shows the operation example of the base station side transmission / reception apparatus 12 under 1st Example. It is a flowchart which shows the operation example of the mobile station side transmission / reception apparatus 4 under 1st Example. It is a figure which shows the example of a frame structure based on 2nd Example. It is a flowchart (the 1) which shows the operation example of the base station side transmission / reception apparatus 12 under 2nd Example. It is a flowchart (the 2) which shows the operation example of the base station side transmission / reception apparatus 12 under 2nd Example. It is a flowchart (the 1) which shows the operation example of the mobile station side transmission / reception apparatus 4 under 2nd Example. It is a flowchart (the 2) which shows the operation example of the mobile station side transmission / reception apparatus 4 under 2nd Example. It is a figure which shows the example of a frame structure based on 3rd Example. It is a flowchart showing the characteristic of 3rd Example. It is a figure which shows the example of a frame structure based on 4th Example. It is a transmission frame block diagram for demonstrating 5th Example. It is a spectrum figure for demonstrating 5th Example. It is a flowchart (the 1) which shows the operation example of the mobile station side transmission / reception apparatus 4 based on 5th Example. It is a flowchart (the 2) which shows the operation example of the mobile station side transmission / reception apparatus 4 based on 5th Example. It is a transmission frame block diagram for demonstrating 6th Example. It is a figure which shows the example of a general flame | frame structure in the mobile communication system which uses a digital modulation system. It is a figure which shows schematic structure of a GPS-AVM system. It is a figure which shows the structural example of the mobile station side transmission / reception apparatus 4 in a GPS-AVM system. It is a figure which shows the structural example of the base station side transmission / reception apparatus 12 in a GPS-AVM system. It is a figure which shows the example of a frame structure by a 1st prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 GPS-AVM system 2 Base station 3 Mobile station 4 Transmission / reception apparatus 5 Speech encoder 6 Speech decoder 7 Control part 8 Digital modulator / demodulator 9 Transmission / reception part 12 Transmission / reception apparatus 13 Voice encoder 14 Transmission control part 15 Digital modulator 16 Transmission part DESCRIPTION OF SYMBOLS 17 Host computer 19 Audio | voice decoder 20 Reception control part 21 Digital demodulator 22 Receiving part 23 Reservation impossible table 30 Super-frame sending means 31 Voice data generation part 32 Transmission frame generation part 33 Super frame generation part

Claims (6)

The data to be transmitted to the receiving side is accommodated by dividing it into a plurality of frames each having the same time length, and assembling consecutive n frames into a frame set, and encoding the voice corresponding to the time length of the frame set. Receiving means for receiving the voice data allocated and arranged for each of the frames exceeding (n / 2) and not more than (n-1) for each frame set;
Demodulation means for demodulating the received audio data;
And a voice output means for outputting the demodulated voice data. The data to be transmitted to the receiving side is accommodated by dividing it into a plurality of frames each having the same time length, and assembling consecutive n frames into a frame set, and encoding the voice corresponding to the time length of the frame set. Voice data is generated,
Non-voice data to be transmitted to the receiving side is allocated to at least one frame, while the voice data is allocated to each frame that exceeds (n / 2) and not more than (n-1) for each frame set. Receiving means arranged to receive audio data and non-audio data transmitted by assigning a unique frame number to each frame; and
Demodulation means for demodulating the received audio data;
And a voice output means for outputting the demodulated voice data. The data to be transmitted to the receiving side is accommodated by dividing it into a plurality of frames each having the same time length, and assembling consecutive n frames into a frame set, and encoding the voice corresponding to the time length of the frame set. Voice data is generated,
Non-voice data to be transmitted to the receiving side is allocated to at least one frame, while the voice data is allocated to each frame that exceeds (n / 2) and not more than (n-1) for each frame set. Receiving means arranged to receive audio data and non-audio data transmitted by assigning a unique frame number to each frame; and
And a generating unit configured to generate a frame to be transmitted to a transmitting side in synchronization with the unique frame number in the received frame set when the frame set is received. The data to be transmitted to the receiving side is accommodated by dividing it into a plurality of frames each having the same time length, and assembling consecutive n frames into a frame set, and encoding the voice corresponding to the time length of the frame set. Audio data is generated and received the audio data allocated and arranged for each frame that exceeds (n / 2) and (n-1) or less for each frame set;
Demodulate the received audio data;
A receiving method comprising outputting the demodulated audio data. The data to be transmitted to the receiving side is accommodated by dividing it into a plurality of frames each having the same time length, and assembling consecutive n frames into a frame set, and encoding the voice corresponding to the time length of the frame set. To generate audio data,
Non-voice data to be transmitted to the receiving side is allocated to at least one frame, while the voice data is allocated to each frame that exceeds (n / 2) and not more than (n-1) for each frame set. Receiving audio data and non-audio data that are arranged and transmitted with a unique frame number assigned to each of the frames;
Demodulate the received audio data;
A receiving method comprising outputting the demodulated audio data. The data to be transmitted to the receiving side is accommodated by dividing it into a plurality of frames each having the same time length, and assembling consecutive n frames into a frame set, and encoding the voice corresponding to the time length of the frame set. To generate audio data,
Non-voice data to be transmitted to the receiving side is allocated to at least one frame, while the voice data is allocated to each frame that exceeds (n / 2) and not more than (n-1) for each frame set. Receiving audio data and non-audio data that are arranged and transmitted with a unique frame number assigned to each of the frames;
A receiving method, comprising: generating a frame to be transmitted to a transmitting side in synchronization with the unique frame number in the received frame set when the frame set is received.

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