Channel equalisation for OFDM using scattered pilots

Channel impairments, such as multipath reflections, can have a profound impact on the bit error rate achievable in OFDM transmission applications. This paper presents a new channel equalisation technique that uses scattered pilots in OFDM symbols to estimate the delay parameters associated with a two-path model as an approximation of a multipath channel. It is applicable for both fixed and mobile reception. Results from simulation studies under multipath Rayleigh channel have shown that the algorithm can offer a substantial performance improvement over that obtained with a conventional linear interpolation approach, used as a benchmark. This is also confirmed by applying the algorithm to data recorded by an OFDM receiver in practical experiments that involved reception of five transmissions of OFDM symbols both 'off air' and through a channel simulator.