초록 ▼

A distortion compensation filtering mechanism for a direct spread-spectrum radio receiver comprises an iteratively adaptive FIR filter installed in the received signal processing path of the radio just upstream of the despreading function. The filter may be implemented as a relatively small numbered

A distortion compensation filtering mechanism for a direct spread-spectrum radio receiver comprises an iteratively adaptive FIR filter installed in the received signal processing path of the radio just upstream of the despreading function. The filter may be implemented as a relatively small numbered tap filter, having its precursor tap fixed at a maximum value. The remaining filter tap values are individually adaptively adjusted by the radio's control processor, which executes a tap adjustment routine to iteratively increment or decrement each variable tap value of the FIR filter to an `optimized' value, that effectively minimizes the total (I and Q) power in the error in the data decisions performed by data signal analyzer.

대표청구항 ▼

1. For use with a direct spread-spectrum radio receiver, in which a demodulated spread signal received by way of a radio transmission channel from another direct spreading radio is processed in accordance with a despreading, pseudo-random chip sequence produced by a pseudo random noise generator to

1. For use with a direct spread-spectrum radio receiver, in which a demodulated spread signal received by way of a radio transmission channel from another direct spreading radio is processed in accordance with a despreading, pseudo-random chip sequence produced by a pseudo random noise generator to produce despread signals, said despread signals being processed by a data signal analyzer to recover transmitted data, a method for compensating for signal degradation effects imparted by said radio channel and internal distortion of said another direct spreading radio and said radio receiver, said method comprising the steps of:(a) filtering said demodulated spread signal by means of an iteratively adaptive multitap finite impulse response (FIR) filter, installed in said receiver upstream of a signal processing location of said direct spread-spectrum radio at which said demodulated spread signal is processed in accordance with said despreading, pseudo-random chip sequence to produce said despread signals; and (b) iteratively adjusting respective tap values of said multitap FIR filter to optimized values that effectively minimize the power in the error in data values produced by said data signal analyzer by setting the value of a selected tap of said multitap FIR filter to a fixed value, and iteratively adjusting tap values of remaining taps of said filter from initial settings to said optimized values, by iteratively adjusting the tap value of each of said remaining taps on. an individual tap basis, from an initial setting to an optimized value for that tap.