| 摘要 |
Apparatus and method employed in a communications system which has a transmitter (2) and a receiver (4), where the receiver determines at which of several rates individual frames in a signal have been transmitted by the transmitter. For example, if the transmitter (2) employs four transmission rates, the receiver (2) decodes each frame of the received signal based on the four rates to produce four cyclic redundancy check (CRC) bits, four symbol error rate (SER) values and one or more Yamamoto check values. If only two of the CRC bits check, then the receiver (2) compares to each other the SER values for those two rates to determine at which of the two rates a current frame was transmitted. If only one of the CRC bits check for a given rate, then the SER value for that rate is compared with a maximum SER threshold for that rate. Additionally, SER values for the other rates ca n be compared to minimum SER thresholds. Furthermore, the Yamamoto check values can be analyzed to determine whether looser or tighter minimum and maximum SER thresholds should be employed if the Yamamoto values check for the current rate, or do not check, respectively. |
