Patent ID: 8462895

Claim:
A receiver for receiving data from a sequence of OFDM symbols transmitted via a channel, each OFDM symbol comprising a plurality of data bearing sub-carriers on which the data is transmitted and a plurality of pilot bearing sub-carriers on which pilot data symbols are transmitted, the pilot sub-carriers being arranged within the OFDM symbols in accordance with a predetermined pilot sub-carrier pattern, the receiver comprising: a channel equalizer including: a pilot data extractor configured to extract received pilot symbols from the pilot sub-carriers of each of the received OFDM symbols, a channel estimator configured to generate an estimate of a channel through which the received OFDM symbols have passed using the received pilot symbols from the received pilot sub-carriers by comparing the received pilot symbols with a version of the pilot symbols transmitted with the OFDM symbols, and a divider configured to reduce the effects of the channel on the received OFDM symbols using the estimate of the channel generated by the channel estimator, so that data can be recovered from the received OFDM symbols, wherein the channel estimator includes: a notch processor configured to detect a notch in a received OFDM symbol, the notch providing a plurality of the sub-carriers of the received OFDM symbol within a frequency range which were not transmitted by the transmitter, to determine one or more missing pilot sub-carriers which would have been transmitted within the notch sub-carriers of OFDM symbols according to the pilot sub-carrier pattern, and to generate a replacement pilot symbol for a pilot data sub-carrier, which would have been transmitted according to the predetermined pattern but was not transmitted as a result of the notch, from one or more other pilot sub-carriers which have been received within OFDM symbols which are not within the notch, and a pilot data interpolator which is arranged in operation to process the received pilot data symbols and the replacement pilot data symbol by interpolating between the received pilot data symbol and the replacement pilot data symbol in time and frequency to produce the estimate of the channel.