Analysis of two receiver schemes for interleaved OFDMA uplink

Abstract

In the uplink of OFDMA (orthogonal frequency division multiple access, a combination of OFDM and FDMA), the interleaved carrier assignment scheme is preferred for its maximum frequency diversity. Two receiver schemes are presented. The first is a group synchronization scheme, in which the uplink receiver compensates the effect of carrier frequency offsets and tries to recover the synchronized spectrum of one OFDMA block. The other one, a user separation scheme, exploits the signal's algebraic structure on the uplink of the interleaved OFDMA system, by which the signal waveform of each single user is separated and synchronized at the same time. We present the algorithms for each scheme and analyze their performance in terms of signal-to-interference-plus-noise ratio and residual interference.