Patent ID: 8170127

Claim:
A receiver for detecting and recovering data from Orthogonal Frequency Division Multiplexed (OFDM) symbols, the OFDM symbols including a plurality of data bearing sub-carriers on which data is transmitted and a plurality of pilot bearing sub-carriers on which pilot data is transmitted, each of the OFDM symbols having been transmitted as a first version of the OFDM symbols via a first channel and a second version of the OFDM symbols via a second channel in accordance with a multiple input-single output system and symbols of the data carried by the sub-carriers of the OFDM symbols are paired to form Alamouti cells, the pairs of data symbols having been encoded differently for the first and second versions of the OFDM symbols in accordance with an Alamouti-type encoding and at least some of the pilot data from the second version being formed as inverted with respect to the corresponding pilot data of the first version of the OFDM symbols, the receiver comprising: a demodulator arranged in operation to detect a signal representing the OFDM symbols, and to generate a sampled version of the OFDM symbols in the time domain; a Fourier transform processor arranged in operation to form a frequency domain version of the OFDM symbols; and a channel estimator and corrector comprising: a pilot data extractor which is arranged to extract the pilot data from the OFDM symbols; a frequency dimension interpolator which is arranged in operation to interpolate between the pilot data received from each the OFDM symbols in the frequency dimension to form sum pilot data and difference pilot data; a sum and difference decoder which is arranged in operation to combine the sum and difference pilot data to form for each pair of data symbols of the Alamouti cells an estimate of a sample of the first channel transfer function and an estimate of the sample of the second channel transfer function; and an Alamouti decoder which is arranged in operation to receive the data bearing sub-carriers from the OFDM symbols and to estimate the transmitted data symbols by performing Alamouti decoding using the estimates of the samples for the first and second channel transfer functions.