Receiver and method of receiving

Abstract

A receiver recovers data from Orthogonal Frequency Division Multiplexed (OFDM) symbols, the OFDM symbols including sub-carrier symbols carrying data symbols and sub-carrier signals carrying pilot symbols. The receiver includes a Fourier transform processor arranged in operation to receive a time domain digital version of the OFDM symbols and to form a frequency domain version of the OFDM symbols, from which the pilot symbol sub-carriers and the data symbol bearing sub-carriers can be recovered, and a detector arranged in operation to recover the data symbols from the data bearing sub-carriers of the OFDM symbols. The receiver includes a noise estimator arranged in operation to generate a long term estimate of noise power in the frequency domain version of the OFDM symbols at a plurality of frequencies, by accumulating an average noise power at the plurality of frequencies from a plurality of the OFDM symbols, and for generating an estimate of a current level of the noise power in the frequency domain version of a current one of the OFDM symbols at the plurality of frequencies. An impulsive noise detector detects the presence of an impulse of noise in the current OFDM symbol, by comparing the noise power in the current OFDM symbol with the long term noise power at the plurality of frequencies, and to generate an impulse noise flag to indicate that the current OFDM symbol is affected by an impulse of noise if the comparison indicates the presence of an impulse of noise. Impulsive noise in the time domain will generate an increase in noise level across the frequency bandwidth of the OFDM symbols. If all frequencies experience an increase then an impulse of noise can be detected. Thereafter the detector can conceal the effect of the impulse noise on the recovering of the data symbols from the data bearing sub-carriers, for example by adapting channel state information for use in de-mapping modulated symbols into data symbols.

Dependencies are inferred from the claim text.