TRANSMITTER METHOD AND TRANSMISSION SYSTEM USING ADAPTIVE CODING BASED ON CHANNEL CHARACTERISTICS

摘要

A transmitter (100) receives information for transmission to a receiver (200) over a communication channel (101). A cyclical redundancy checking (CRC) code circuit (106) encodes the information with CRC code for error detection purposes. The CRC coded information is provided to a code switch (108). The code switch (108) provides the CRC coded information to either a first code circuit (110) or a second code circuit (112) forward error correction (FEC) coding. The first code circuit (110) may, for example, encode the information using a FEC Code 1, such as convolutional coding, and the second code circuit (112) may encode the information using a FEC Code 2, such as repetition coding. The code switch (108) selects either the first or second code circuit (110 or 112) based on detected characteristics of the channel (101). The channel characteristics may be obtained from a channel estimation circuit (114), may be obtained from an error feedback signal I3 from the receiver (200) or may be obtained from a combination of both. After the code switch (108) selects the first or second code circuit (110 or 112), the information is appropriately coded to produce a coded signal which is transmitted over the channel (101) by a transmission circuit (116).