Method and apparatus for indicating a temporary block flow to which a piggybacked ack/nack field is addressed

Abstract

A method and an apparatus for indicating a temporary block flow (TBF) to which a piggybacked acknowledgement/non-acknowledgement (PAN) field is addressed. A method and apparatus of performing receive processing to reduce the probability of false acceptance of erroneous PANs are also disclosed. A transmit station generates a PAN check sequence (PCS) and performs a channel coding on a PAN field and the PCS. The transmit station scrambles the encoded bits of the PAN field and the PCS with a TBF-specific scrambling code. Because of the scrambling, the PCS decoding at a receive station will pass if the data block is received by an intended receive station, while the PCS decoding will fail if received by a non-intended receive station. Alternatively, the scrambling may be performed before the channel coding. Alternatively, the transmit station may combine the PAN field and a temporary flow identity (TFI) to generate a PCS.

What is claimed is: 
     
         1 . A method for processing a received data block, the method comprising:
 receiving a data block including coded bits of a first field and a second field, wherein the second field is a cyclic redundancy check (CRC) checksum of the first field;   decoding the coded bits of the first field and the second field;   performing a metric test by comparing a metric computed during the decoding of the coded bits with a threshold;   performing a CRC test; and   determining that the first field is properly decoded on a condition that a result of the metric test and a result of the CRC test are acceptable.   
     
     
         2 . The method of  claim 1  wherein the metric is a best survivor path metric in Viterbi-type forward error correction decoding. 
     
     
         3 . The method of  claim 1  wherein the metric is a difference between a best survivor path metric and a second best survivor path metric in Viterbi-type forward error correction decoding. 
     
     
         4 . The method of  claim 1  wherein the metric is a bit error rate. 
     
     
         5 . The method of  claim 1  wherein the first field is a piggybacked acknowledgement/non-acknowledgement (PAN) field included in a data block to indicate either an acknowledgement (ACK) or a non-acknowledgement (NACK). 
     
     
         6 . The method of  claim 1  further comprising:
 descrambling the coded bits with a scrambling code. 
 
     
     
         7 . An apparatus for processing a received data block, the apparatus comprising:
 a receiver configured to receive a data block including coded bits of a first field and a second field, wherein the second field is a cyclic redundancy check (CRC) checksum of the first field;   a decoder configured to decode the coded bits of the first field and the second field;   a metric test unit configured to perform a metric test by comparing a metric computed during the decoding of the coded bits with a threshold; and   a CRC decoder configured to perform a CRC test, wherein the first field is determined to be properly decoded on a condition that both a result of the metric test and a result of the CRC test are acceptable.   
     
     
         8 . The apparatus of  claim 7  wherein the metric is a best survivor path metric in Viterbi-type forward error correction decoding. 
     
     
         9 . The apparatus of  claim 7  wherein the metric is a difference between a best survivor path metric and a second best survivor path metric in Viterbi-type forward error correction decoding. 
     
     
         10 . The apparatus of  claim 7  wherein the metric is a bit error rate. 
     
     
         11 . The apparatus of  claim 7  wherein the first field is a piggybacked acknowledgement/non-acknowledgement (PAN) field included in a data block to indicate either an acknowledgement (ACK) or a non-acknowledgement (NACK). 
     
     
         12 . The apparatus of  claim 7  further comprising:
 a descrambler configured to descramble the coded bits with a scrambling code.