Energy-efficient Hardware Architecture and VLSI Implementation of a Polyphase Channelizer with Applications to Subband Adaptive Filtering

Polyphase channelizer is an important component of subband adaptive filtering systems. This paper presents an energy-efficient hardware architecture and VLSI implementation of polyphase channelizer, integrating algorithmic, architectural and circuit level design techniques. At algorithm level, low complexity polyphase channelizer architecture is derived using multirate signal processing approach. To reduce the computational complexity in polyphase filters, computation sharing differential coefficient (CSDC) method is effectively used as an architectural level technique. The main idea of CSDC is to combine the strength of augmented differential coefficient method and subexpression sharing. Efficient circuitlevel techniques: low power commutator implementation, dual-VDD scheme and novel level-converting flip-flop (LCFF), are also used to further reduce the power dissipation. The proposed polyphase channelizer consumes 352 mW power with throughput of 480 million samples per second (MSPS). A test chip has been fabricated in 0.18 μm CMOS technology and its functionality is verified. Chip measurement results show that the dual-VDD implementation achieves a total power saving of 2.7 X.