METHOD AND APPARATUS FOR PROVIDING ERROR PROTECTION FOR OVERTHE AIR FILE TRANSFER

摘要

In a communication system which conforms to the IS-99 standard, a concatenat ed code is used to provide for error free file transfer over the air. The concatenated code comprises Reed-Solomon coding (22), CRC block coding (32), and convolutional coding (36). At the transmitter, the file is partitioned into data frames and Reed-Solomon encoding (22) is performed on the data frames. CRC block encoding is then performed on the Reed-Solomon encoded data. The CRC encoded data is convolutionally encoded (36). The CRC block encoding (32) and convolutional encoding are performed in accordance with th e IS-99 standard. The additional Reed-Solomon encoding step provides improved error correction capability while maintaining compatibility with the IS-99 standard. At the receiver, Reed-Solomon decoding (104) is performed if the number of erasures in a code word is less than or equal to (n-k) or the symbol errors in a code word is less than or equal to (n-k)/2. Otherwise, a request for retransmission is sent.