Apparatus and method for channel encoding/decoding in a communication system
An apparatus and method for channel encoding/decoding are provided which vary an iterative decoding number according to service type, data class and channel condition. A message information receiver receives information about a message to be received. A controller determines an iterative decoding number according to the message information received. A decoder iteratively decodes the received message according to the determined iterative decoding number. The message information includes a class of received data, and the class includes a bit error rate (BER). The iterative decoding number is increased for a low BER as compared to a predetermined BER. Further, the class includes a permissible time delay, and the iterative decoding number is increased for a long permissible time delay as compared to a predetermined permissible time delay. In addition, the message information includes a service type of the received data, and the iterative decoding number is decreased when the service type is a moving picture service.
1. A receiving device for a communication system, comprising:
a message information receiver for receiving information about a message to be received;
a transmission channel receiver for receiving the message;
a controller for determining an iterative decoding number according to the message information received from the message information receiver; and
a decoder for iteratively decoding the message received from the transmission channel according to the determined iterative decoding number.
2. The receiving device as claimed in claim 1 , wherein the message information includes a class of received data.
3. The receiving device as claimed in claim 2 , wherein the class includes a bit error rate (BER).
4. The receiving device as claimed in claim 3 , wherein the controller increases the iterative decoding number if the BER is less than a predetermined number.
5. The receiving device as claimed in claim 2 , wherein the class includes a permissible time delay.
6. The receiving device as claimed in claim 5 , wherein the controller increases the iterative decoding number if the permissible time delay is greater than a predetermined number.
7. The receiving device as claimed in claim 1 , wherein the message information includes a service type of the received data.
8. The receiving device as claimed in claim 7 , wherein the controller decreases the iterative decoding number if the service type is a moving picture service.
9. The receiving device as claimed in claim 1 , wherein the decoder is a soft-decision decoder.
10. The receiving device as claimed in claim 1 , wherein the decoder is a MAP (Maximum A Posteriori Probability) decoder.
11. The receiving device as claimed in claim 1 , wherein the decoder is a SOVA (Soft Output Viterbi Algorithm) decoder.
12. A receiving method for a communication system, comprising the steps of:
receiving information about a message to be received;
receiving the message through a channel;
determining an iterative decoding number according to the information; and
iteratively decoding the received message according to the determined iterative decoding number.
13. The receiving method as claimed in claim 12 , wherein the message information includes a data class of the received data.
14. The receiving method as claimed in claim 13 , further comprising the step of decreasing the iterative decoding number if the data class of the received data is a low data class.
15. The receiving method as claimed in claim 13 , wherein the class includes a BER.
16. The receiving method as claimed in claim 13 , further comprising the step of decreasing the iterative decoding number if the BER is greater than a predetermined number.
17. The receiving method as claimed in claim 13 , wherein the data class includes a permissible time delay.
18. The receiving method as claimed in claim 17 , further comprising the step of decreasing the iterative decoding number if the permissible time delay is less than a predetermined number.
19. The receiving method as claimed in claim 12 , wherein the message information includes a service type of the received data.
20. The receiving method as claimed in claim 19 , further comprising the step of decreasing the iterative decoding number if the service type is a moving picture service.