Patent ID: 6717976
Filing Date: 2004-04-06
Classification: H04B,H04J,H04W

Abstract:
An apparatus for generating a control signal suitable to regulate a transmission power of a transmitter generating a CDMA signal transported in a main channel including a plurality of sub-signals transported in respective subchannels of the main channel, said apparatus including:a plurality of demodulators that receive the CDMA signal, wherein each demodulator despreads the CDMA signal to produce a despread CDMA signal, wherein each demodulator covers the despread CDMA signal with a plurality of Walsh codes respective to the subchannels, and wherein each demodulator produces a plurality of demodulator outputs, wherein each demodulator output respective to one of the plurality of sub-signals, and wherein each of the plurality of demodulators includes: a despreader that despreads the CDMA signal based upon at least one of a long code and a short code to produce the despread CDMA signal; a plurality of multipliers each of which mixes the despread CDMA signal with the plurality of Walsh codes corresponding to the plurality of subchannels; and a plurality of symbol accumulators, each of which couples to an output of a respective multiplier and produces a respective demodulator output; a combiner functional block that receives the plurality of demodulator outputs from the plurality of demodulators and combines the plurality of demodulator outputs to produce the plurality of sub-signals; an SNR estimator functional block operatively coupled to the combiner functional block for receiving the plurality of sub-signals, wherein the SNR estimator functional block computes an estimate of a ratio of a total signal energy in the plurality of sub-signals to a total noise energy in the plurality of sub-signals; and a logical functional block coupled to said SNR estimator functional block to generate at an output the control signal suitable to regulate the transmission power of the transmitter generating the CDMA signal in dependence of the estimated ratio of a total signal energy in the plurality of sub-signals to a total noise energy in the plurality of sub-signals computed by said SNR estimator functional block.