| 摘要 |
A receiver to detect and recover payload data received as Orthogonal Frequency Division Multiplexed (OFDM) symbols 1801, each frame including a preamble including multiple bootstrap symbols. From one or more of the bootstrap symbols synchronisation timing for converting a useful part of the bootstrap symbols into the frequency domain is detected. A bootstrap processor detects, using the signature sequence, a frequency offset of the received signal and an estimate of the channel transfer function from a first of the bootstrap symbols, and a demodulator is configured to recover the signalling data from the one or more bootstrap symbols using the estimate of the channel transfer function. The bootstrap processor up-samples 1802 the received bootstrap symbols to form an up-sampled frequency domain version of the bootstrap symbol, comprising for each sub-carrier of the first bootstrap symbol a plurality of U samples representing each of the sub-carriers of the bootstrap symbol, a cross-correlator 1804 configured to cross-correlate a signature sequence, which was combined with the first bootstrap symbol at the transmitter, with the up-sampled version of the first bootstrap symbol to generate for each of the sub-carriers of the up-sampled version of the OFDM symbol a correlation result, the peak correlation result 1814 is identified and used to determine the frequency offset of the received signal from a relative position of the peak correlation result in the frequency domain in accordance with a sub-carrier bandwidth of the up-sampled version of the bootstrap symbol. |
