Patent ID: 6243415
Filing Date: 2001-06-05
Classification: H04B,H04L

Abstract:
Process of multisensor equalization in a radio receiver which includes an array of sensors and a spatial filter coupled to a temporal filter which perform filtering using plural coefficients, the radio receiver performing demodulation, in the presence of multiple propagation paths and interference sources, on a received serial digital modulated message which includes frames of learning and information sequences, the process comprising:digitizing a signal received by each sensor;transforming each digitized signal into a baseband signal;filtering each baseband signal by low-pass filtering to produce a filtered signal;synchronizing each filtered signal in order to obtain an estimate of useful paths of the signal and an estimate of a frequency shift in each filtered signal;compensating for the frequency shift in each filtered signal, based on the estimate of the frequency shift, to produce a compensated signal;calculating the coefficients of the spatial filter and using the spatial filter to filter and sum each compensated signal to produce a spatial filtered signal;calculating the coefficients of the temporal filter and using the temporal filter to filter a replica signal and produce a temporal filtered signal, wherein the replica signal includes known symbols in a learning sequence or demodulated symbols in an information sequence;iterating the steps of calculating the coefficients of the spatial and temporal filters so as to minimize under a predetermined constraint, a mean square error between the spatial filtered signal and the temporal filtered signal;equalizing the spatial filtered signal by one-dimensional equalization at a symbol rate at which transmitted symbols are decided; andwherein the coefficients of the spatial and temporal filters and coefficients of an equalizing filter used in the equalizing step are updated according to a predetermined sequencing of the frames.