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

4 A 4 1 0 ~ 0 . 8 = 8 ~ ~ .id 1 1.6 + 2 x 3.2 = 8 p Abstract Timing synchronization for IEEE 802.1 l a KLANs 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 signijicant requirement can be eliminated by using multiplierless correlators. In this paper, multiplierless correlators are designed based on constraining the real and imaginaly parts of correlator coeficients to be sums of powers of two. Sets of coeficients that yield good synchronization performance for simple A WGN channels are first identified; then their goodness for indoor communication environments is veriJied by simulation for multipath fading channels. Several multiplierless correlators are found. Comparison among these correlators ident$es a good one that requires to perfom only 26 additionhbtraction operations per correlator output while a similar synchronization pevformance can be maintained.' Index Terms Low-complexity implementation, Multiplierless correlator, Timing synchronization, Wireless local area network.