A new multiplierless correlator for timing synchronization in IEEE 802.11a WLANs

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 the 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 suitability 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 is required to perform only 26 addition/subtraction operations to generate one correlator output while a similar synchronization performance can be maintained.