Design of multiplierless correlators for timing synchronization in IEEE 802.11a wireless LANs

Timing synchronization for IEEE 802.11a WLANs requires using a correlator to correlate the received signal with a known waveform. Straightforward implementation of this correlator results in the need to perform 320 million complex multiplications per second. This significant requirement can be eliminated by using multiplierless correlators. In this paper, multiplierless correlators are designed based on constraining the real and imaginary parts of correlator coefficients to be sums of powers of two. Sets of coefficients that yield good synchronization performance for simple AWGN channels are first identified; then their goodness for indoor communication environments is verified by simulation for multipath fading channels. Several multiplierless correlators are found. Comparison among these correlators identifies a good one that requires to perform only 26 addition/subtraction operations per correlator output while a similar synchronization performance can be maintained.