KR20010048949A - Method for multiplexing low bit rate of channels to high bit rate frame - Google Patents

Abstract

PURPOSE: A method of multiplexing multiple low bit rate channels with a high bit rate is provided which transmits one channel over multiple frames in a communication system to multiplex multiple low bit rate channels with a high bit rate. CONSTITUTION: One channel is split into first predetermined number of basic channels for row transmission rate data in a low delay code excited linear prediction mode. The second predetermined number of different basic channels are loaded in a time slot of a multiplexing frame having a predetermined transmission rate. The first predetermined number of multiplexing frames construct one channel, and the third predetermined number of multiplexing frames form one transmission period. A signal information transmission mode according to the transmission of the data channel is set in accordance with the number of entire channels based on the transmission period.

Description

METHOD FOR MULTIPLEXING LOW BIT RATE OF CHANNELS TO HIGH BIT RATE FRAME}

The present invention relates to a method of multiplexing low bit rate channels at a high bit rate and to a computer readable recording medium recording a program for realizing the method, in particular low delay code excitation linear prediction (LD-CELP: Low). A computer readable recording of a method of multiplexing a frame having a bit rate of 2048 kilobits per second (kbps) for a channel encoded by the Delay Code Excited Linear Prediction method and a program for realizing the method. It is about the medium.

Pulse Code Modulation (PCM) and Adaptive Differential Pulse Code Modulation (ADPCM) are the Telecommunication part of International Telecommunication Union (ITU-T). The basic unit of encoding as specified in Recommendations G.711 and G.726 is 125 ms. This is a method of sampling and quantization and encoding.The 2048kbps frame structure for multiplexing 64kbps channel using PCM and 32kbps channel using ADPCM is specified in the ITU-T series of recommendations. Follow this recommendation.

The LD-CELP method is specified in ITU-T Recommendation G.728. It is a method of predicting a speech signal and encoding the predicted error signal by selecting the most suitable value among the prepared values. to be. That is, data is encoded every 625 ms. The prepared value (code) is 10 bits and has a baud rate of 16 kbps.

Since the frame structure for multiplexing is not specified for the channel conforming to the LD-CELP encoding method, it is difficult to efficiently transmit and receive through a transmission path by accepting an LD-CELP encoded channel in a 2048kbps frame between different communication devices. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a method for multiplexing multiple channels of low bit rate at a high bit rate by transmitting one channel over several frames in a communication system and a program for realizing the method. Its purpose is to provide a computer readable recording medium having recorded thereon.

That is, in the present invention, in order to multiplex the LD-CELP-coded channel into 2048 kbps frames, the basic channels are divided into 2048 kbps frames so that each LD-CELP channel fits into a 2048 kbps frame structure. It is an object of the present invention to provide a method of multiplexing and applying a computer-readable recording medium recording a program for realizing the method.

1 is an exemplary configuration diagram of a communication system to which the present invention is applied.

2 is an illustration of one embodiment of channel multiplexing used in a method of multiplexing multiple low bitrate channels at a high bitrate in accordance with the present invention.

3 is an illustration of one embodiment of a multiplexed frame in a method of multiplexing multiple low bitrate channels at a high bitrate in accordance with the present invention;

4 is a diagram illustrating an embodiment of a timeslot for signal information in a method of multiplexing a low bit rate channel into a high bit rate according to the present invention.

5 is a flow diagram of an embodiment of a method of multiplexing multiple low bit rates channels to a high bit rate in accordance with the present invention.

* Explanation of symbols for the main parts of the drawings

100: multiplexer 200: demultiplexer

A method of the present invention for achieving the above object is a method for multiplexing a low bit rate multiplexing channel applied to a communication system at a high bit rate, one for the data of the low rate code excitation linear prediction (LD-CELP) method Dividing the channels of the first channel into a first predetermined number of base channels; A second step of loading a second predetermined number of different basic channels in a timeslot of a multiplexed frame having a predetermined transmission rate; A third step of forming one channel through the first predetermined number of multiplexed frames and a transmission period of a third predetermined number of multiplexed frames; And a fourth step of setting and multiplexing a signal information transmission method according to transmission of the data channel according to the total number of channels according to the transmission period.

In addition, another method of the present invention is a method for multiplexing multiple low bit rate channels applied to a communication system at a high bit rate, wherein one LD-CELP method has 16 kilobits per second (kbps). Dividing the channel into five basic channels; A second step of loading four different base channels in a timeslot of a multiplex frame having a transmission rate of 2048 kbps; A third step of forming one channel through the five multiplexed frames and one transmission period of the 15 multiplexed frames; And a fourth step of setting and multiplexing a signal information transmission method according to transmission of the data channel according to the total number of channels according to the transmission period.

In addition, the present invention provides a communication system having a high-capacity processor, comprising: a first function of dividing one channel into a first predetermined number of base channels for low-rate code excitation linear prediction (LD-CELP) data; A second function of loading a second predetermined number of different basic channels in a timeslot of a multiplexed frame having a predetermined transmission rate; A third function of forming said one channel through said first predetermined number of said multiplexed frames and achieving a transmission period of said third predetermined number of said multiplexed frames; And

A computer-readable recording medium having recorded thereon a program for realizing a fourth function of setting and multiplexing a signal information transmission method according to transmission of the data channel according to the total number of channels according to the transmission period is provided.

In addition, the present invention provides a communication system having a high-capacity processor, comprising: a first function of dividing one channel into five basic channels for LD-CELP data having a 16 kilobit / second transmission rate (kbps); A second function of loading four different base channels in timeslots of multiplexed frames having a transmission rate of 2048 kbps; A third function of forming one channel through the five multiplexed frames and one transmission period of the 15 multiplexed frames; And a computer-readable recording medium having recorded thereon a program for realizing a fourth function of setting and multiplexing a signal information transmission method according to transmission of the data channel according to the total number of channels according to the transmission period.

In the 2048kbps frame, it is possible to receive and transmit the channel encoded by LD-CELP method, not the conventional coding method (PCM method or ADPCM method) for the acceptable channel, thereby maximizing the transmission / reception efficiency of transmission path As a result, the overall efficiency of the communication system can be improved.

The electrical / physical characteristics of the 2048kbps frame in the present invention are in accordance with ITU-T Recommendation G.703, and items not mentioned such as the general characteristics and structure of the 2048kbps frame are in accordance with ITU-T Recommendation G.704.

The present invention accommodates both common channel signaling and channel combined signaling for generalization of signaling information. However, a, b, c, and d of the channel combination signaling method is used in a specific country, so it will not be described, and a and b signaling methods, which are generally used worldwide, will be described. The coding scheme applied in the present invention is Low Delay Code Excited Linear Prediction (LD-CELP), one channel is composed of 10 bits, and the transmission rate of the channel is 16 kbps. The time required for coding one channel before multiplexing is 625 ms.

In the present invention, terms are defined as follows to avoid confusion of terms.

The 8-bit minimum access unit is called one timeslot. That is, one timeslot is one octet.

In transmission, the minimum channel unit is 2 bits, which is called a basic channel (Bc).

The gist of the present invention divides basic channels, which are the minimum channel units, for each channel requiring multiplexing, and finally derives a 2048kbps frame by using each basic channel as an input of a multiplexer.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary configuration diagram of a communication system to which the present invention is applied.

An input of the multiplexer 100, that is, an input of a transmission side channel, refers to a channel encoded by the LD-CELP scheme. Communication between the multiplexer 100 and the demultiplexer 200 is performed by wire or wirelessly. The output of the demultiplexer 200, that is, the receiving side channel, has the same coding scheme and transmission rate as the output of the transmitting side channel.

The LD-CELP encoding method requires an encoding time of 625 ms per channel, and one 2048 kbps frame has a channel allocation time of 125 ms, so that one channel can be multiplexed over five frames. That is, the multiplexing cycle for one channel is once every five frames, and the maximum number of channels for configuring five frames is 116. The input to the multiplexer 110 is a 10-bit channel encoded by the LD-CELP scheme having a 16kbps transmission rate.

Here, the maximum number of channels is 116 because only 3 timeslots out of 32 timeslots of 2048kbps frames are used for cyclic redundancy check (CRC) and signal information transmission. Because it is sent.

FIG. 2 is a diagram illustrating an embodiment of channel multiplexing used in a method for multiplexing a low bit rate channel into a high bit rate according to the present invention.

One channel composed of 10 bits is composed of five basic channels through the multiplexer 100. The mapping of the channel to the basic channel Bc is shown in the following [Table 1].

1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 bit 8 bit 9 bit 10 bit Bc1 / 5 Bc2 / 5 Bc3 / 5 Bc4 / 5 Bc5 / 5

The five basic channels shown in [Table 1] constitute one 10-bit channel using LD-CELP encoding with a 16kbps transmission rate, where "Bc1 / 5" is the first 2048kbps frame and "Bc2 / 5" is In the second 2048kbps frame, "Bc3 / 5" is multiplexed in the third 2048kbps frame, Bc4 / 5 in the fourth 2048kbps frame, and Bc5 / 5 in the fifth 2048kbps frame in order of channel number. This is also shown through the channel multiplexing diagram shown in the figure.

3 is a diagram illustrating an embodiment of a multiplexed frame in a method of multiplexing multiple low bitrate channels at a high bitrate according to the present invention.

One channel occupies two bits each of five frames. Time slots for multiplexing the basic channels are timeslots 1 to 15 and timeslots 18 to 31.

3 shows multiplexing of each channel into 2048kbps frames for 15 frames. As shown in FIG. 3, the multiplexing is performed on one channel for 625 ms, and the data using the same channel is multiplexed three times for 1.875 ms. That is, multiplexing is performed three times for one channel for 15 frames.

Time slot 0 is in accordance with ITU-T Recommendation G.704 Table 5A / 5B.

Time slot 15 is multiplexed in the same way as time slot 1 so that channels 57, 58, 59, and 60 are multiplexed.

Time slots 16 and 17 are timeslots for signal information.

Time slot 18 is multiplexed in the same way as time slot 1, whereby channels 61, 62, 63, and 64 are multiplexed.

Time slot 31 is multiplexed in the same way as time slot 1 so that channels 113, 114, 115, and 116 are multiplexed.

Each time slot is explained in more detail as follows.

Time slot 0 is defined in ITU-T Rec. G.704, Tables 5A and 5B, with either the CRC scheme adopted (Table 5B) or the non-adopted (Table 5A). When the CRC scheme is adopted, a 16-frame multiframe structure is used. This is called a multiframe structure for CRC checking. In the present invention, time slot 0 can accommodate both of the above cases.

In FIG. 3, times 16 and 17 are for signal information, and can accommodate a common channel signal method and a channel combined signal method. In the case of the channel combination signaling method, a multiframe consisting of 15 consecutive frames numbered from 0 to 14 is required. (The multiframe structure is called a multiframe structure for signal information. The multiframe structure based on the timeslot is called a multiframe structure for CRC check). The period of the signal information for each channel at this time is 1.875 ms. Bit designation is described with reference to the following FIG. 4.

4 is a diagram illustrating an embodiment of a timeslot for signal information in a method of multiplexing a low bit rate channel into a high bit rate according to the present invention.

FIG. 4 shows the bit details for the channel-combined signaling schemes of times 16 and 17 in a multiplexing method of a 16-kbps channel into a 2048-kbps frame using the LD-CELP coding scheme.

Here, bits 5, 7, and 8 of the timeslot 16 of frame 0 are fixed to 1 when they are not used as spare bits.

Bit 6 of time slot 16 of frame 0 is a remote alarm indication (RAI) bit, where 0 indicates a steady state and 1 indicates an alarm state.

5 is a flow diagram of an embodiment of a method of multiplexing multiple low bit rates channels to a high bit rate in accordance with the present invention.

One channel consisting of 10 bits is divided into five basic channels every two bits for LDB-CELP data of 16 kbps (501).

In the frame of 2048kbps, four basic channels are loaded in one time slot (502).

Time slot 0 is used in accordance with ITU-T Recommendation G.704 Table 5A / 5B. Time slots 16 and 17 are used to transmit signal information, so 4 channels will be loaded in the remaining 29 timeslots. .

Five frames are required to allow multiplexing of one channel. There are three such five frames, so that 15 frames that can be multiplexed three times in one channel are multiframes of one cycle (503). Of course, in the case of CRC checking, 16 frames are included as one frame by including one more frame.

In operation 504, it is determined which signal method is to be used as the signal method used to transmit the signal information.

As a result of determining which signal method is to be used, when the common channel signal method is used, the method used in the existing 2048kbps frame is used (505).

As a result of determining which signaling method to use, the channel-combined signaling method uses time slot 16 of frame 0 for synchronization, reserved bits and remote alarm indication bits for a frame of one period (506). Time slots 16 and 17 except for time slot 16 of frame 0 of the frame are used to transmit signal information of each channel (507).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

As described above, the present invention uses the 2048kbps frame to multiplex the 16kbps channel using the LD-CELP coding scheme, which is not specified in the ITU-T Recommendation Series, thereby limiting the coding scheme for the existing acceptable channel. In addition, there is an effect of receiving and transmitting a channel encoded by the LD-CELP scheme in a 2048kbps frame.

In addition, the present invention, by accepting the channel encoded by the LD-CELP method in a frame of 2048kbps, there is an effect that can maximize the transmission and reception efficiency of the transmission line, resulting in the overall efficiency improvement of the communication system.

Claims (6)

In a method of multiplexing multiple low bit rate channels applied to a communication system at a high bit rate, A first step of dividing one channel into a first predetermined number of base channels for low-rate code excitation linear prediction (LD-CELP) data; A second step of loading a second predetermined number of different basic channels in a timeslot of a multiplexed frame having a predetermined transmission rate; A third step of forming one channel through the first predetermined number of multiplexed frames and a transmission period of a third predetermined number of multiplexed frames; And A fourth step of setting and multiplexing a signal information transmission method according to transmission of the data channel according to the total number of channels according to the transmission period A method of multiplexing a low bit rate of multiple channels comprising a high bit rate. The method of claim 1, The fourth step, A fifth step of selecting and confirming which signal information transmission method to use when multiplexing the data channel; And When the signal information transmission method of the channel combined signal method is used, two bits of the data transmission time slots of the remaining frames except the one time slot for signal transmission of one frame for one multiframe are allocated by 2 bits for the data channel. Sixth step of transmitting signal information A method of multiplexing a low bit rate of multiple channels comprising a high bit rate. In a method of multiplexing multiple low bit rate channels applied to a communication system at a high bit rate, A first step of dividing one channel into five basic channels for LD-CELP data having a 16 kilobit per second (kbps); A second step of loading four different base channels in a timeslot of a multiplex frame having a transmission rate of 2048 kbps; A third step of forming one channel through the five multiplexed frames and one transmission period of the 15 multiplexed frames; And A fourth step of setting and multiplexing a signal information transmission method according to transmission of the data channel according to the total number of channels according to the transmission period A method of multiplexing a low bit rate of multiple channels comprising a high bit rate. The method according to claim 1 or 3, One transmission period of the third step, A method of multiplexing multiple low bit rate channels at a high bit rate, comprising one frame for cyclic redundancy check (CRC). In a communication system having a large capacity processor, A first function of dividing one channel into a first predetermined number of base channels for low rate code excitation linear prediction (LD-CELP) data; A second function of loading a second predetermined number of different basic channels in a timeslot of a multiplexed frame having a predetermined transmission rate; A third function of forming said one channel through said first predetermined number of said multiplexed frames and achieving a transmission period of said third predetermined number of said multiplexed frames; And A fourth function of setting and multiplexing a signal information transmission method according to transmission of the data channel according to the total number of channels according to the transmission period A computer-readable recording medium having recorded thereon a program for realizing this. In a communication system having a large capacity processor, A first function of dividing one channel into five basic channels for LD-CELP type data having a 16 kilobit / second transmission rate (kbps); A second function of loading four different base channels in timeslots of multiplexed frames having a transmission rate of 2048 kbps; A third function of forming one channel through the five multiplexed frames and one transmission period of the 15 multiplexed frames; And A fourth function of setting and multiplexing a signal information transmission method according to transmission of the data channel according to the total number of channels according to the transmission period A computer-readable recording medium having recorded thereon a program for realizing this.