Patent ID: 7949037

Claim:
A base station for carrier-offset recovery during reception of a communication signal over an air interface using a reduced pilot signal, the base station comprising: an adaptive matched filter configured to produce a filtered signal of the received signals, the adaptive matched filter being provided with filter coefficients for filtering; a rake receiver configured to provide relative path values of a plurality of multipath components of data on a selected channel in the received signals; a mixer configured to mix a correction signal with outputs from the rake receiver to generate channel impulse response estimates which works as the filter coefficients of the adaptive matched filter; a channel despreader for the selected channel coupled to the adaptive matched filter output configured to despread the filtered signal using the pseudo-noise signal generated for the selected channel to produce a despread channel signal of the selected channel; a pilot channel despreader for a pilot channel coupled to the adaptive matched filter output configured to despread the filtered signal using a pseudo-noise signal generated for the pilot channel to produce a despread pilot signal of the pilot channel; a hard decision processor configured to determine a symbol value of the despread channel signal of the selected channel in accordance with a modulation constellation; a complex conjugate processor configured to generate a complex conjugate of the symbol value generated by the hard decision processor, the complex conjugate of the symbol value becoming the correction signal; a phase-locked loop configured to produce a phase correction signal by measuring a phase difference of the despread pilot signal, the phase correction signal being mixed with the received signals to recover carrier offset.