Patent ID: 6570939
Filing Date: 2003-05-27
Classification: H04L

Abstract:
A receiving device comprising:an oscillator generating a frequency different from a carrier frequency by (2n+Â½)&ohgr;0, provided that n is an integer, &ohgr;0=2Î /T, and T is a transmission rate of a base band signal; a mixer combining a reception signal and the signal having the frequency generated by said oscillator; a filter for filtering the signal synthesized by said mixer; an A/D converter sampling the signal passed through said filter at every T/2 so as to convert the signal into a digital signal for output; a polarity signal generator generating a polarity signal of which polarity inverts at every sample; a multiplier multiplying the signal having been outputted from said A/D converter and the polarity signal having been generated by said polarity signal generator, the resultant signal destined for output; a selector dividing up the output signal from said multiplier between a signal at time nT and a signal at time (n+Â½)T, which are destined for output; and a maximum likelihood sequence estimating equalizer using maximum likelihood sequence estimation for estimating a transmission signal sequence on the basis of the output signal from said selector, said maximum likelihood sequence estimating equalizer having a transmission line estimating section calculating an impulse response of the transmission line on the basis of the output signal from said selector, a replica generator calculating a replica on the basis of the impulse response of the transmission line having been calculated by said transmission line estimation section, a branch metric arithmetic section for calculating a branch metric indicating a difference between the output signal from said selector and the replica having been calculated by said replica generator, and a signal sequence estimating section using maximum likelihood sequence estimation in order to estimate the transmission signal sequence.