JPH08288924A - Multiplexed digital voice processing circuit - Google Patents

Abstract

PURPOSE: To provide the multiplexed digital voice processing circuit in which both a full rate and a half rate signal are processed and processing of a maximum channel is executed similarly to the half rate signal even in the case of the full rate signal. CONSTITUTION: When 1st channel control information is operated by a full rate signal, a voice signal processing section 11 operates a highway changeover switch 41 by a control output to switch a highway bus X system into a Y system and coded voice highways 61, 62 are connected to a voice signal processing section 21 . Simultaneously the voice signal processing section 21 is operated by the full rate signal. When all channels of coded voice highways 51, 52 are operated by the full rate signal, voice signal processing sections 21 -2n are all connected to the coded voice highways 61, 62 and operated in the full rate mode operation and then all the voice signal processing sections 11 -1n and 21 -2n are in operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplexed digital voice processing circuit, and more particularly to a multiplexed digital voice processing circuit in a digital mobile telephone system which operates in two types of voice modes, a half rate voice mode and a full rate voice mode. .

[0002]

2. Description of the Related Art In digital car telephone systems, the full-rate system has been popular from the past. However, with the rapid increase in demand for car telephones in recent years, one coded line is used in order to use the limited frequency more effectively. A half-rate system, which can double the number of channels multiplexed in each time slot of an audio highway as compared with the full-rate system, is being put to practical use. However, since the full-rate method and the half-rate method are not compatible with each other in the voice coding algorithm, etc., and it is considered that they will all shift to the half-rate method in the future, so in the transition period when the full-rate method shifts to the half-rate method. A voice processing circuit that can be shared by the methods is required.

FIG. 4 shows a block diagram of a conventional multiplexed digital voice processing circuit. This conventional multiplexed digital audio processing circuit includes 2n audio signal processing units 1 ₁ to _12n provided in parallel, and these audio signal processing units 1 ₁
1 to _12n in common, the audio signal processing units 1 ₁ to _12n are connected to the encoded audio highway 5.

The voice signal processing units 1 ₁ to _12n have the same configuration, and a pulse code modulated (PCM) voice signal, that is, a PCM encoded voice signal is input to an input terminal Pi and encoded into a full rate and a half rate. With
The encoded signal is decoded into a PCM encoded voice signal and output from the output terminal Po. Further, the timing generation circuit 3
The 2 MHz highway clock HC and the 8 kHz frame pulse FP are input, and the input / output timing clock is supplied to the audio signal processing unit 1i (i = 1 to 2n) based on these. The coded voice highway 5 is a coded voice highway having a plurality of time slots in which data and control information are multiplexed n times at a half rate.

In the half-rate digital MTS, 12 channels at a half rate are multiplexed in one time slot of the encoded voice highway, and the voice processing card functions as 12 channels at a half rate and 6 channels at a full rate. Is possible (in the case of 2n = 12).

Here, when all are in the full rate operation mode, one time slot of the coded voice highway is six.
Since the number of channels is reduced to 1/2 and the timing from the timing generation circuit 3 to each of the audio signal processing units 1 ₁ to _12n is the same, the six audio signal processing units 1 ₁ to ₁₆ must execute full-rate processing. become.

[0007]

However, in this conventional multiplexed digital voice processing circuit, a PCM coded voice signal is converted into a low bit rate full rate coded signal and a half rate coded signal obtained by further compressing it into half. Both can be processed, but in the case of all full rates, only half of the channels at half rate can be processed, and when using only full rate, half of the audio signal processing part is unused, It is uneconomical.

The present invention has been made in view of the above points,
It is possible to process both a PCM coded audio signal into a low bit rate full rate coded signal and a half rate compressed half rate coded signal, and even in the case of full rate, processing of the maximum channel is similar to half rate. An object is to provide a multiplexed digital voice processing circuit that can be implemented.

[0009]

In order to achieve the above-mentioned object, the present invention encodes an input audio signal into a full rate or a half rate to generate an encoded signal, outputs the encoded signal together with control information, and inputs the encoded signal. A first audio signal processing unit that decodes an encoded signal into an audio signal, and performs a full-rate or half-rate-dedicated process on an audio signal that is input according to control information from the first audio signal processing unit. Together with a second audio signal processing section for outputting monitoring information indicating a processing state,
A timing generation unit that supplies an input / output timing signal to the first and second audio signal processing units, and a highway changeover switch that selectively switches an encoded highway signal based on control information indicating an operation state of the first audio signal processing unit. And a plurality of time slots in which a plurality of sets of data and control information are multiplexed at the time of half rate, which are always connected to the first audio signal processing unit, and are connected to the second audio signal processing via the highway changeover switch. And a second encoded voice highway connected to the second voice signal processing unit via a highway changeover switch at full rate. .

[0010]

According to the present invention, the first and second audio signal processing sections have a master / slave configuration, and the first audio signal processing section connected to the first encoded audio highway is operated at full rate during full rate operation. On the other hand, the second audio signal processing unit is fixedly operated at the full rate, and the second audio signal processing unit performs the second operation via the highway changeover switch.
Connected to the encoded voice highway.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows a block diagram of an embodiment of a multiplexed digital voice processing circuit according to the present invention. In the figure, the same components as those in FIG. 4 are denoted by the same reference numerals. As shown in FIG. 1, in this embodiment, the audio signal processing units 1 ₁ to
1 _n , the timing generation circuit 3, the encoded voice highway 5 (51 and 52), and the voice signal processing units 1 ₁ to
A highway changeover switch 4 for selectively switching the coded highway signal according to the states of the voice signal processing units 2 ₁ to 2 _n and the voice signal processing units 1 ₁ to 1 _n , which performs dedicated processing for full rate or half rate depending on the state of 1 _{n. 1} to 4 _n and the second coded voice highway 6 (61) connected at the full rate
And 62) are provided. In FIG. 1, the encoded voice highways 51 and 61 are downlink encoded voice highways DHWA and DHWB, respectively.
, And encoded voice highways 52 and 62 are upstream encoded voice highways UHWA and UHWB, respectively.
Indicates.

The audio signal processing units 2 ₁ to 2 _n have control lines for control and status monitoring corresponding to the audio signal processing units 1 ₁ to 1 _n in a ratio of 1: 1. ₁ to 2 _n control output terminal _{C o} and status monitoring input terminal ST _i of the recipient are connected to the audio signal processing unit ₁ 1 to 1 _n control input terminals _{C i} and condition monitoring output terminal ST _o the.

Further, the output terminals O and the input terminals I of the highway changeover switches 4 ₁ to 4 _n are connected to the control input terminals CO _i and the control output terminals CO _o of the audio signal processing sections 2 ₁ to 2 _n to select them. Highway changeover switch 4 ₁ to 4 _n
Terminals X and Y of the coded voice highways (HWA) 51 and 52 and the coded voice highways (HWB) 61 and 62.
Is connected. Coded voice highways (HWA) 51 and 52 are connected to the control input terminals CO _i and the control output terminals CO _o of the voice signal processing units 1 ₁ to 1 _n .

The full-rate and half-rate encoded signals in the encoded voice highways (HWA) 51 and 52 are represented by 32 time slots (T) as shown in FIG.
S) constitutes one frame, and each time slot has a frame synchronization bit (MF for full rate, HMF for half rate) arranged at the beginning as shown in FIG. Control information area 11 ₁ and data area 12 ₁ are arranged. Similarly, control information areas 11 _{2 to} 11 _N and data area 12 ₂ are arranged in the order of channels.
.About.12 _N sets are sequentially arranged, and a total of N (= 2n) are multiplexed.

When all channels are transmitted at the half rate, n = 6 as shown in FIG. 2 (C).
In the case of, each information of all channels CH1 to CH12 is multiplexed in each of 320 frames (40 ms),
When all channels are transmitted at full rate, channels 1 to 6 CH1 to CH as shown in FIG.
6 information is transmitted.

Next, the operation of this embodiment will be described for the case where n = 6. First, when all of the 12 channels are in the half rate operation state, the highway changeover switches 4 ₁ to 4 _n control the highway bus to the X system to cause the audio signal processing units 2 ₁ to 2 _n to be encoded audio highways 51 and 52. Connected to.

Further, the PCM-encoded voice signal input to the respective input terminals P _i of the voice signal processing units 1 ₁ to 1 _n is encoded from the output terminal CO _o at the timing determined by the half rate method. The signal is output to the encoded voice highway 51, and the encoded signal input from the encoded voice highway 52 to each input terminal CO _i of the voice signal processing units 1 ₁ to 1 _n is decoded here. The decoded audio signal is output from the output terminal P _o .

The PCM-encoded audio signals input to the respective input terminals P _i of the audio signal processing units 2 ₁ to 2 _n are output from the output terminal CO _o at the timing determined by the half rate method. and outputs it to the coded speech highway 51 via a highway selector switch 4 ₁ to 4 _n provided correspondingly.

Further, the audio signal processing unit 2 from the coded speech highway 52 via a highway selector switch 4 ₁ to 4 _n
The coded signal input to each of the input terminals CO _i of _{1 to} 2 _n is the coded signal of the time slot defined by the half rate method, and the decoded signal is output from the output terminal P _o. Output.

As a result, the time slots of the coded voice highways (HWA) 51 and 52 processed by the voice signal processing units 1 ₁ to 1 _n and 2 ₁ to 2 _n in the half rate operation state are shown in FIG. As shown in, information CH1 to CH1 from the first channel in 320 frames
CH12 is sequentially multiplexed.

The only control information of the first channel in this state becomes a full-rate operation, the audio signal processing unit 1 ₁ is an output control signal of the control output terminal C _o ON (H level).
Then, highway selector switch 4 ₁ is operated, the switching to the Y-bus highway from X system until then, the audio signal processor 2 ₁ The coded speech highways 61 and 62 via a highway selector switch 4 ₁ Switched and connected. At the same time, because the audio signal processing unit 2 _first control input terminal C _i to H level is input, the audio signal processor 2 ₁ performs the operation of the full rate only (control information half rate mistakenly Ignore it if you receive it.).

In addition, the encoded voice highways 61 and 62
Since it is a full rate only when the CH1 is the call mode, the audio signal processor 2 ₁ executes a full rate operation,
To the status monitoring output terminal ST _O ON (H level). Then, the audio signal processing unit 1 ₁ receives the above H-level to the control state monitoring input terminal ST _i, the audio signal processor 2
_{1 determines} that the full rate operation is being executed, and while receiving the H level, the transition to the half rate is prohibited and the currently operating speech line is prioritized.

In this case, the encoded voice highway (HW
A) The signal format of TS1 of 51 and 52 is shown in FIG.
As shown by F in (B), CH1 and processed by the audio signal processing unit _{1 1} to the position of CH7 or processed CH
Are arranged one full-rate information, TS1 signal format of the coded speech highways (HWB) 61 and 62, FIG. 3 audio signal processing unit _{2 1} at a position corresponding to the position of the CH1 and CH7 as shown in (C) The full-rate information of the seventh channel processed or processed by is arranged.

Similarly, the encoded voice highway (HW
A) When CH3 of 51 and 52 becomes full rate operation,
The audio signal processing unit 1 ₂ is on the output control signal of the control output terminal C _o (H level), the bus highway selector switch 4 ₂ highway switch to the Y-from X-system, the audio signal processor 2 ₂ Is the encoded voice highways 61 and 6
2 is connected, together with the audio signal processor 2 ₂ performs the operation of the full rate only (erroneously receives control information of a half rate ignored.), And on (H level) and the condition monitoring output terminal ST _O To do.

In this way, when all the channels of the coded voice highways (HWA) 51 and 52 are in the full rate operation, the voice signal processing units 2 ₁ to 2 _n are all changed to the coded voice highways (HWB) 61 and 62. As a result, the TS1 of the encoded voice highways (HWA) 51 and 52 are connected to each other to operate in the full rate mode. As shown in FIG. 3D, full rate information is arranged in all channel positions, and the encoded voice is encoded. The signal format of TS1 of the highways (HWB) 61 and 62 is as shown in FIG. 3 (E), and all the audio signal processing units 1 ₁ to 1 _n and 2 ₁ to 2 _n will operate.

Audio signal processing units 1 ₁ to 1 _n and 2 ₁ to 2 _n
When the control of the above is performed by an external bus, the audio signal processing unit 1
A control line for control and state monitoring between ₁ to 1 _n and the audio signal processing units 2 ₁ to 2 _n is not particularly required, but when in-band control as shown in FIG. Is required.

[0027]

As described above, according to the present invention,
During the full-rate operation, the first audio signal processing unit connected to the first encoded audio highway is operated at the full rate, while the second audio signal processing unit is fixedly operated at the full rate and the second audio signal is operated. Since the processing unit is connected to the second encoded voice highway via the highway changeover switch, all of the first and second voice signal processing units can be operated at full rate during full rate operation,
It is possible to effectively use the audio signal processing unit.

[Brief description of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a diagram showing a frame structure and a format of a coded voice highway.

FIG. 3 is a diagram showing an example of channel configurations within one time slot in FIG.

FIG. 4 is a block diagram of an example of a conventional multiplexed digital voice processing circuit.

[Explanation of symbols]

1 ₁ to 1 _n , 2 _{1 to} 2 _n voice signal processing unit 3 timing generation unit 4 ₁ to 4 _n highway changeover switch 51, 52 first coded voice highway (HWA) 61, 62 second coded voice highway (HWB)

Claims (2)

[Claims] 1. A first audio signal that encodes an input audio signal at a full rate or a half rate to generate an encoded signal and outputs the encoded signal together with control information, and decodes the input encoded signal into an audio signal. A processing unit, and a second audio signal processing unit that performs full-rate or half-rate-dedicated processing on the audio signal input according to the control information from the first audio signal processing unit and outputs monitoring information indicating a processing state. An audio signal processing unit, a timing generation unit that supplies an input / output timing signal to the first and second audio signal processing units, and encoding based on the control information indicating an operation state of the first audio signal processing unit. A highway switch for selectively switching a highway signal, and a plurality of time slots in which a plurality of sets of data and control information are multiplexed at a half rate, and the first sound is provided. A first coded audio highway that is always connected to a signal processing unit and that is connected to the second audio signal processing unit via the highway changeover switch; and a first coded audio highway at full rate via the highway changeover switch. And a second encoded voice highway connected to two voice signal processing units. 2. The multiplexed digital signal according to claim 1, wherein the second audio signal processing section and the highway changeover switch are respectively provided corresponding to the first audio signal processing section. Audio processing circuit.