Reduced latency channel-estimation

A receiver for an OFDM signal including a series of OFDM symbols, each symbol having a plurality of sub-carriers, each sub-carrier being modulated by at least one data bit encoded with an error-correcting code, the receiver comprising:

• a first error-correcting decoder, adapted to decode sequentially the data bits of a received first OFDM symbol;
• a re-encoder, arranged to receive decoded bits from the first decoder and adapted to re-encode a leading portion of the decoded bits;
• a mapper, arranged to receive the re-encoded leading portion of bits from the re-encoder, map these bits to a corresponding subset of the plurality of sub-carriers, and thereby estimate a modulation symbol that was applied to each sub-carrier of said subset, by the transmitter;
• a channel estimator, adapted to produce a channel estimate by comparing the sub-carrier modulation symbols estimated by the mapper with the corresponding sub-carriers actually received by the receiver;
• and
• an equalizer, adapted to process the received signal to remove distortions introduced by the transmission channel, using the channel estimate,
• wherein the re-encoder is adapted to begin re-encoding the leading portion of the bits before a trailing portion of the bits has been decoded by the decoder;
• and
• wherein
• the leading portion of bits decoded from the first OFDM symbol is combined with a trailing portion of bits decoded from a preceding OFDM symbol;
• and
• the channel estimator is adapted to produce a channel estimate based on the combined portions.