AN APPARATUS AND METHOD FOR ADAPTIVE DIGITAL LOCKING AND SOFT EVALUATION OF DATA SYMBOLS IN A WIRELESS DIGITAL COMMUNICATION SYSTEM

摘要

A data communication system detects a synchronization signal and a start pattern, and extracts data symbols form a serially encoded digital data stream transmitted to a receiver (30). The communication system transmission apparatus that includes a frame formatter (10), which generates a frame of symbols of serially encoded data to be transmitted. The comunication system has a receiving apparatus in communication with tha transmission apparatus to axquire the series of symbols. THe receiving apparatus has a register (55) in communication with a sample and hold circuit (45) to receive the series of symbols composed of a plurality of bits resulting from the sampling of the signal received by the sample and hold circuit (45). Upon receipt of the plurality of bits, location of the bits is adjusted within the register (55). A symbol evaluator (60) is in comunication with the register (55) to examine the plurality of bits to determine a symbol value for the plurality of bits. The symbol value includes a synchronization value, a start value, and a data value. The synchronization value indicates the synchronization pattern indicating the timing of the signal. The start value indicates the start pattern at the beginning og the data message. The data value indicates at least one of the dual-bit data symbols of the data message. The symbol value is a most probable value of all possible symbol values.