Channel-independent equalizer device

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【作者】 Dent  Paul W. 

【摘要】A demodulator for demodulating a signal modulated with digital information symbols so as to extract the information symbols is disclosed. A receiver receives a signal over a communications channel. Samplers and digitizers then produce a sequence of numerical sample values representative of the received signal. Memories are provided each having a number of state memories each associated with a hypothesized symbol string. A controller selectively retrieves values from the memories and controls the timing of operations thereupon. A metric computer computes candidate metrics using a hypothesis of a next of the information symbols to be demodulated made by the controller, one of the numerical sample values, path metric values, B-matrices, and U-vectors and the candidate metrics associated state number selected by the controller from the memories. A best predecessor computer determines the best of the candidate metrics to be selected to be written back into the memory means along with a successor B-matrix, U-vector and path history. The successor B-matrices, U-vectors and path history are then updated using corresponding values associated with the best predecessor and one of numerical sample values.