Analog correlation technique for ultra-low power receivers

摘要

A correlation unit comprising: a plurality of sampling stages each configured to sample a received baseband signal; a plurality of correlation stages, downstream of the sampling stages, each comprising: a first switching integrator including a first switch coupled to a first integration capacitor; a second switching integrator including a second switch coupled to a second integration capacitor; a control code source configured to generate control signals associated with each correlation stage based on bit shifted versions of a predetermined correlation code sequence, wherein the control signals associated with each correlation stage include the first and second switches in response to values of the bit shifted correlation code selectively opening and closing, wherein the sampled baseband signal is selectively provided to the first and second integration capacitors to accumulate first and second voltage potentials, respectively, over a plurality of sample clock periods; and a plurality of comparison units configured to receive the first and second voltage potentials within respective correlation stages and to evaluate an analog correlation result therefrom.