MXPA98009880A

MXPA98009880A - Transmission rate judgment method and apparatus

Info

Publication number: MXPA98009880A
Application number: MXPA/A/1998/009880A
Authority: MX
Inventors: Nakano Takayuki
Original assignee: Matsushita Electric Ind Co Ltd
Priority date: 1997-11-26
Filing date: 1998-11-25
Publication date: 2002-05-09

Abstract

Symbol repetition number counting section 108 counts the number of received symbol repetitions and decoding order determination section 109 determines the decoding order for anticipated rates in the high-to-low order of likelihood of each rate being the transmission rate of the received symbol based on the counted symbol repetition number.

Description

TRANSMISSION SPEED JUDGMENT METHOD AND ITS APPARATUS FIELD OF THE INVENTION The present invention relates to methods of judging the transmission speed and its apparatuses.

BACKGROUND OF THE INVENTION Recently, with the dramatically increasing demands of terrestrial mobile communications such as car phones and portable telephones, great importance is attributed to a technology that allows the effective use of frequencies to ensure capabilities for the largest possible number of subscribers with limited frequency bands . As one of the multiple access systems for the effective use of frequencies, the multiple access system with code division (CDMA system) is attracting attention. The CDMA system is a multiple access system that uses a communications technology with an extended signal spectrum capable of achieving excellent communication quality through its wide band and its high correlation characteristics using the pseudo-series of noise (PN), etc. Terrestrial mobile communication systems using the CDMA system are described, for example, in REF .: 28985 Patent No. 4901307 of the US. A mobile communication system using the CDMA system can increase the capacity of the system by introducing the variable transmission speed. For example, in CODEC of the variable speed sound, the data rate changes in units of a 20 millisecond section called "frame" according to the sound activity. Transmitting only the amount of information necessary to send the corresponding sound signal in each frame makes it possible to reduce interference with other users and increase the capacity of the system as well. On the transitive side, after coding, the system adds a CRC bit to check the quality of the frame, for example, and performs convolutional coding. The convolutionally coded data are repeated according to the data rate and have frames of the same length regardless of the data rate. After processing as well as block interleaving, propagation and modulation, the data is transmitted. Then, with reference to the drawings, a conventional transmission speed judgment apparatus is explained below. Figure 1 is a sectional diagram of a conventional transmission speed judgment apparatus. In Figure 1, the conventional transmission speed judging apparatus judges a transmission rate using the variable speed decoding section 501. This variable rate decoding section 501 comprises the derequest section 502 which combines or adds the repeated symbols according to the speed to be demodulated, the Viterbi decoding section 503 which performs Viterbi decoding on the output symbol of the section 502 of derequest and outputs the decoded data, and the CRC checking section 504 which performs a CRC check on the Viterbi decoded data. It also comprises the convolutional coding section 505 which performs the convolutional coding on the output of the Viterbi decoding section 503 and the counter number 506 of symbolic errors which calculates the number of symbolic errors in a frame using the output of the section 502 of derepetition and the output of section 505 of convolutional coding. It also comprises the judgment section 507 of the speed judging the speed based on the CRC check result and the reliability and the number of symbolic errors of Viterbi decoding. The sections from the replay section 502 to the counter count section 506 of symbolic errors can perform the processing according to the multiple anticipated data rates, for example, maximum speed, speed 1/2, speed 1/4 and speed 1/8 Since the data rate varies from one frame to another, the system performs this processing for all speeds or some speeds, and estimates and judges the transmission speed. Then, with reference to Figure 2 and Figure 3, the speed judgment procedure is explained. Figure 2 is a flow chart demonstrating the procedure for decoding a received symbol and judging the speed. As shown in Figure 2, then? performing the respective processing from the derequest section 502 to the counter portion 506 of symbolic errors for all the anticipated speeds (step 601), the system forms a judgment according to the result (step 602). In step 602, this method forms a judgment using the quality information of all speeds, i.e., CRC check results, Viterbi decoding reliability and number of symbolic errors of all speeds. Figure 3 is a flow chart showing the procedure for judging speed by decoding each speed and quality judgment. As shown in Figure 3, the system carries out the processing from the derequest section 502 to the counter section 506 of the number of symbolic errors sequentially beginning with a specific speed and forms a judgment in the process. In step 701, it performs processing from the deregulation section 502 to the counter portion 506 of symbolic errors for the speed with the greatest amount of information (maximum speed), and in step 702 forms a judgment based on the quality information of the maximum speed. If the outcome of the trial is acceptable, the system judges it as a maximum speed (step 710) and the process ends here. If the judgment result is unacceptable, the system carries out the processing from section 502 of derepetition to section 506 of counter of number of symbolic errors for a speed 1/2 that has half the amount of speed information. maximum (step 703) and in step 704 form a judgment based on the quality information of the speed 1/2. The speed judgment is continued in this way by repeating the same sequential processing. However, the conventional transmission rate judgment apparatus mentioned above needs to carry out decoding for all speeds or multiple speeds, resulting in a problem of increasing the amount of processing and consequently increasing the consumption of electric power. For battery-operated devices, for example portable terminals in particular, an increase in the consumption of electric power leads to a decrease in the duration of conversation and waiting time.

BRIEF DESCRIPTION OF THE INVENTION The present invention has been implemented taking into account the aforementioned problem and it is an object of the present invention to provide a method of judging the transmission speed and an apparatus for that purpose which will reduce the amount of average decoding processing, making it possible to reduce the consumption of electrical energy. The present invention detects the number of repetitions of the received symbols, determines the priority of the transmission rates in the decoding of the received signal based on this number of repetitions of the symbol and decodes the received symbol at this determined transmission speed. This configuration allows the decoding to be carried out starting with a speed that has the highest probability of being the transmission speed of the received symbol, making it possible to omit the unnecessary decoding processing. This results in a reduction in the consumption of electrical energy.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a sectional diagram showing the configuration of a judgment apparatus of the conventional transmission speed; Figure 2 illustrates a general flow diagram of a judgment method of the conventional transmission speed and judgment procedure of its apparatus; Figure 3 illustrates a detailed flow chart of the judgment method of the conventional transmission speed and judgment procedure of its apparatus; Figure 4 illustrates a sectional diagram showing the configuration of the transmission speed judgment apparatus according to the embodiment 1 of the present invention; Figure 5 illustrates a flow diagram of the method of judging the transmission rate according to the mode 1 of the present invention; Figure 6 illustrates a sectional diagram showing the configuration of the transmission speed judgment apparatus according to mode 2 of the present invention; and Figure 7 illustrates a flow diagram of the method of judging the transmission rate according to the method 2 of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES With reference now to the attached drawings, the embodiments of the present invention are explained below: (Mode 1) The judgment apparatus of the transmission speed according to the mode 1 of the present invention counts the number of repetitions of the received symbol, determines the priority for the anticipated speeds based on the counted number of repetitions of the symbol, decodes the received symbol based on this priority, judges the quality and determines the transmission speed. Figure 4 is a sectional diagram showing the configuration of the transmission speed judgment apparatus according to the embodiment 1 of the present invention. As shown in Figure 4, the transmission rate judgment apparatus according to the mode 1 of the present invention judges the transmission rate using the variable rate decoding section 101. This variable rate decoding section 101 comprises the derepression section 102 which combines a received symbol according to the number of repetitions corresponding to the specified speed, the Viterbi decoding section 103 which carries out the Viterbi decoding on the output of this derequest section and produces the decoded data, and the CRC checking section 104 which carries out a CRC check on the Viterbi decoding section 103. It also comprises the convolutional coding section 105 carrying out the convolutional coding on the output of the decoding section Viterbi 103 and the counter number section 106 of symbolic errors which counts the number of symbolic errors using the output of the section 102 of derepetition and the output of section 105 of convolutional coding. Furthermore, it comprises the judgment section 107 of the speed judging the transmission speed based on the CRC check result which is the output of the CRC 104 check section, the quality information in the Viterbi decoding section 103 and the number of the symbolic errors that is the output of the counter section 106 of number of symbolic errors. And further comprises the repetition number counter section 108 of the symbol counting the number of repetitions of the received symbol and the section 109 of determining the decoding order that determines the decoding order based on the counted number of repetitions of the symbol. In the received symbol that has been subjected to demodulation and depropagation processing, the same symbol is repeated when the transmission speed is low. For example, if the symbol is transmitted without being repeated at the speed with the maximum amount of information (maximum speed), the same symbol is repeated twice at a speed that has half the amount of information of the maximum speed (speed 1/2). Also, at a speed 1/4, the same symbol is repeated 4 times; speed 1/8, 8 times. Based on this repetition rule, the repetition number counter section 108 of the symbol calculates the probability (probability of being the transmission speed of the received symbol) for each of the anticipated speeds. At a speed of 1/8, for example, calculate the number of symbols with the same code among 8 symbols. The higher the probability that the transmission speed of the received symbol is the speed 1/8. The probability of other speeds can be calculated in the same way. The decoding order determination section 109 determines the decoding order of the speed based on the probability of these speeds. In mode 1, the decoding is carried out in the order of the highest to the lowest of the speed. The system performs processing from the deregulation section 102 to the counter count section 106 of symbolic errors according to this order and judges speeds sequentially. Then, the speed judgment procedure is explained with reference to the flow diagram in Figure 5 below. In step 201, the number of repetitions of the symbol is calculated to find the probability of each velocity. . In step 202, the decoding order, ie, of which speed the decoding is started, is determined based on this probability. The velocity with the highest probability is designated as the first velocity; the second highest probability, the second speed; the third highest probability, the third speed; the fourth highest probability, the fourth speed. In step 203, the processing is performed from the deregulation section 102 to the seizure error number counter section 106 sequentially for the first speed to obtain the speed quality information, i.e. the CRC check result , reliability of decoding Viterbi and number of symbolic errors. In step 204, the speed is judged on the basis of the quality information. If the judgment result is acceptable, the first speed is judged as the transmission speed of the received symbol (step 212) and the process ends here. If the judgment result is unacceptable, sequential processing is carried out from the derepetition section 102 to the counter count section 106 of symbolic errors for the second velocity to obtain the quality information of the velocity. Then, in step 206, the speed is judged based on the quality information of the second speed. The speed judgment is continued in this way by repeating the same sequential processing. In this way, according to the modality 1, the decoding order determination section 109 carries out the decoding and the judgment beginning with the speed that has the highest probability of being the transmission speed of the received symbol, making it possible to reduce the amount of average decoding processing and prevent an increase in the consumption of electric power. (Mode 2) Thus, the transmission speed judgment apparatus according to mode 2 of the present invention is explained below. The judgment apparatus of the transmission rate according to the mode 2 of the present invention measures the level of a received symbol, determines the priority for the anticipated speeds based on the measured reception level, decodes the received symbol based on this priority, judge the quality and determine the transmission speed. Figure 6 is a sectional diagram showing the configuration of the transmission rate judgment apparatus according to mode 2 of the present invention. As shown in Figure 6, the judgment apparatus of the transmission rate according to mode 2 of the present invention is provided with the measurement section 308 of the reception level which measures the level of a symbol received, the section 309 for determining the decoding order determining the decoding order based on the measured reception level, instead of the repeating number counter section 108 of the symbol and the decoding order determining section 109 in the modality 1 mentioned above. The rest of the configuration is the same as that of mode 1 and its explanations are omitted here. The energy of the received symbol that has been subjected to demodulation and depropagation processing is reduced when the transmission speed is low. For example, a speed that has half the amount of information (speed 1/2) of the maximum speed that has the maximum amount of information has energy 1/2. Also, a 1/4 speed has 1/4 energy; speed 1/8, energy 1/8. The reception level measuring section 308 measures the level of the received symbol and the decoding order determining section 309 determines the decoding order of the speed based on this measured level. Compare the level of reception of the corresponding frame and the anticipated level of each speed, designates the speed with the closest level as the first speed and other speeds as from the second to the fourth speed in the order of the proximity of the level. According to this order, the processing is carried out sequentially from the derepetition section 102 to the counter number section 106 of symbolic errors to judge speeds sequentially. Then, the speed judgment procedure is explained with reference to the flow diagram in Figure 7 below. In step 401, the reception level is measured to find the probability of each velocity. In step 402, the order of speed decoding is determined based on this probability. The velocity with the highest probability is designated as the first velocity; the speed with the second highest probability, the second speed; the speed with the third highest probability, the third speed; the fourth highest probability, the fourth speed. In step 403, the processing is carried out sequentially from the deregulation section 102 to the number 106 counter of symbolic error number for the first speed to obtain the quality information of the speed, ie the result of the CRC check , reliability of decoding Viterbi and number of symbolic errors. In step 404, the speed is judged on the basis of the quality information. If the judgment result is acceptable, the first speed is judged as the transmission speed of the received symbol (step 412) and the process ends here. If the judgment result is unacceptable, the processing is sequentially carried out in step 405 from the derepetition section 102 to the counter count section 106 of symbolic errors for the second speed to obtain the quality information of the velocity. Then, in step 406, the speed is judged based on the quality information of the second speed. The speed judgment is continued in this way by repeating the same sequential processing. In this way, according to the modality 2, the decoding order determining section 309 carries out the decoding and judgment beginning with the speed that has the highest probability of being the transmission speed of the received symbol, making it possible to reduce the amount of average decoding processing and prevent an increase in the consumption of electric power. As it is clearly understood from the above explanation, the present invention allows the quality judgment to start from the speed that has the highest probability of being the transmission speed of the received symbol, facilitating the determination of the transmission speed and reducing the amount of transmission. average processing. This results in a reduction in the consumption of the electrical energy of the apparatus, and consequently an extension of the waiting time.

It is noted that in relation to this date, the best method known by the applicant to carry out the present invention is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property:

Claims

1. A method of judging the transmission speed characterized in that it counts the number of repetitions of the received symbol and determines the priority of the transmission speed in the decoding of the received symbol based on this repetition count.

2. A transmission speed judgment method characterized in that it measures the level of a received symbol and determines the priority of the transmission speed in the decoding of the received symbol based on this measured level.

3. A speed judgment apparatus characterized in that it comprises a counter means of repetition of the symbol for counting the number of repetitions of the received symbol and a means of determining the speed to determine the priority of the transmission speed in the decoding of the received symbol based on the said repetition count of the symbol.

4. The transmission speed judgment apparatus according to claim 3, characterized in that said speed determining means determines the priority of the transmission speed based on the repetition count of the received symbol and determines the transmission speed used for decoding according to this priority.

5. A transmission speed judgment apparatus characterized in that it comprises a means of measuring the reception level for measuring the level of a received symbol and a means of determining the speed to determine the priority of the transmission speed in the decoding of the symbol received based on said level.

• The transmission speed judgment apparatus according to claim 5, characterized in that the speed determining means determines the priority of the transmission speed based on the level of the received symbol and determines "the transmission speed. used for decoding according to this priority.

7. A reception apparatus characterized in that it comprises the transmission speed judgment apparatus according to claim 3, a quality judgment means for judging the quality of decoded data and an output means for producing the judgment result of this means of quality judgment.

8. A reception apparatus characterized in that it comprises the transmission speed judgment apparatus according to claim 5, a quality judgment means for judging the quality of decoded data and an output means for producing the judgment result of this means of quality judgment.

9. The receiving apparatus according to claim 7, characterized in that it comprises a means of derepetition to combine the symbol received in the repetition count corresponding to the specified speed, a Viterbi decoding means for carrying out the Viterbi decoding on the said output. derepression means, a CRC check means for carrying out a CRC check on the output of said Viterbi decoding means, a convolutional coding means for carrying out the convolutional coding on the output of said Viterbi decoding means, a counter means of number of symbolic errors to count the number of symbolic errors of the output of said means of derepetition and the output of said means of convolutional coding, and a means of judgment of the speed to judge the transmission speed based on the CRC check result which is the output of the said checking means eo CRC, the quality information in the said Viterbi decoding means and the number of symbolic errors that is the output of said symbol counter number of symbolic errors.

10. A mobile communication terminal device characterized in that it comprises the receiving apparatus according to claim 7 and carries out the radio communication with a base station apparatus.

11. A base station communication apparatus characterized in that it comprises the receiving apparatus according to claim 7 and carries out the radio communication with a mobile station communication terminal apparatus.

12. A communication system characterized in that it comprises the mobile communication terminal apparatus according to claim 10 and the mobile base station communication device according to claim 11.

13. A decoding method characterized in that it counts the number of repetitions of the received symbol, determines the priority of the transmission speed in the decoding of the received symbol based on this repetition count of the symbol and decodes the received symbol at this determined transmission speed.

14. A decoding method characterized in that it measures the level of a received symbol, determines the priority of the transmission speed in the decoding of the received symbol based on this measured level and decodes the received symbol at this determined transmission speed.