CHANNEL IMPULSE RESPONSE ESTIMATOR FOR USE IN AN ADAPTIVE MAXIMUM LIKELIHOOD SEQUENCE ESTIMATION RECEIVER WHICH IS APPLICABLE TO A COMMUNICATION SYSTEM HAVING A CHANNEL CHARACTERISTIC WITH RAPID FLUCTUATION

摘要

In a channel impulse response estimator (12), a local preamble generator (35) generates a local preamble signal identical with a transmission preamble signal in a received signal. A preamble detector (37) detects the transmission preamble signal in an estimated sequence signal to produce a preamble detection signal. Responsive to the preamble detection signal, a sequence selector (39) selects one of the local preamble signal and the estimated sequence signal as a selected sequence signal which is supplied to a re-modulator (14). Responsive to the preamble deection signal, a step-size generator (41) generates one of first and second step-size signals as a selected step-size signal which is supplied to a tap coefficient producer (26). IMAGE