DIGITAL COMMUNICATION SYSTEM HAVING IMPROVED PILOT ENCODING

摘要

A time division multiple access communication system (10) is provided having multiple sub-channels according to known quadrature amplitude modulation techniques. Each sub- channel has a pre-determined time duration and is divided by a pre- determined number of symbol position time divisions. The symbol positions carry color codes and ACP codes in addition to sync, pilot and data symbols. Pilot symbols in the second half of the slot are replaced with dual purpose color code and ACP symbols. The dual purpose symbols are either modulated with a lower order modulation than data symbols or are repeated values of dedicated symbols located earlier in the same slot, or both. Slot throughput is attained with a minimal bit error rate penalty.