Novel Low-Power Switched-Current Matched Filter for Direct-Sequence Code-Division-Multiple-Access Wireless Communication

Abstract

We have proposed the current-cut switched-current matched filter (CC-SIMF) with a low power consumption of less than 10 mW for mobile terminals in direct-sequence code-division-multiple-access. The parallel SIMF configuration is proposed for the reduction of the current transfer error accumulation in the conventional serial SIMF. In order to evaluate the fundamental operation of the parallel SIMF, we have designed and fabricated a 32-chip parallel SIMF using 0.8-µm complementary-metal-oxide-semiconductor (CMOS) technology. The autocorrelation performance of a 32-chip orthogonal m-sequence has been clearly observed to be more than 5 Mcps. The measured dynamic range is improved to 12 dB as compared with that of the conventional SIMF, even though each current memory cell has a current transfer error of over 10% per chip. Since the current sources in the parallel SIMF can be reduced to be one-third of those in the serial SIMF, the power consumption of the parallel SIMF can be reduced to one-third of that of the serial SIMF.