An Area-Efficient 4-Stream FIR Interpolation/Decimation for IEEE 802.11n WLAN

This paper presents an area-efficient 4- stream finite impulse response (FIR) interpolation/decimation for IEEE 802.11n wireless local area network (WLAN). Novelty of the presented design is threefold. First, a multi-path pipelined polyphase structure is proposed to deal with multiple data streams, thereby four simultaneous data streams can be supported in the design with minimal hardware complexity. Second, a hybrid common subexpression elimination (HCSE) method that using signed binary representation of coefficients is applied to the implementation of subfilters. The multiplications in each subfilter are efficiently implemented using a few hardwired shifts, adders, and subtracters. And last, the interpolating mode and decimating mode of the design are configurable. That help to improve system level hardware utilization efficiency since WLAN is a time division duplex system. Under 0.13 mu m 1.2 V 1P6M CMOS technology, the cell area and power consumption of the presented interpolation/decimation are 0.22 mm(2) and 10.08 mW respectively. The error vector magnitude (EVM) performance of an 802.11n baseband prototype which adopts the presented design is measured -42.2 dB.