Transmitters, receivers and methods of transmitting and receiving

A receiver configured to recovering data from Orthogonal Frequency Division Multiplexed (OFDM) symbols,

• wherein the OFDM symbols include a plurality of sub-carrier signals, some of the sub-carrier signals carrying data symbols and some of the sub-carrier signals carrying pilot symbols, the pilot symbols comprising continuous pilot symbols, the continuous pilot symbols being distributed across the sub-carrier signals in accordance with a continuous pilot symbol pattern, the receiver comprising:
• a demodulator configured to detect a signal representing the OFDM symbols, and to generate a sampled digital version of the OFDM symbols in the time domain,
• a Fourier transform processor configured to receive the time domain digital version of the OFDM symbols and to form a frequency domain version of the OFDM symbols, from which the pilot symbol bearing sub-carriers and the data symbol bearing sub-carriers can be recovered, and
• a detector configured to recover the data symbols from the data bearing sub-carrier signals of the OFDM symbols and to recover the pilot symbols from the pilot bearing sub-carrier signals of the OFDM symbols, wherein the detector comprises a memory configured to store data relating to a pilot pattern and a processor configured to detect the number of sub-carrier signals in the plurality of sub-carrier signals and to derive the continuous pilot pattern from the pilot pattern data based on the number of sub-carrier signals, and the OFDM symbols comprise
• first OFDM symbols, which include a first number of sub-carriers signals, and
• second OFDM symbols, which include a second number of sub-carrier signals, the second number of second sub-carrier signals being the same or greater than the first number of sub-carrier signals, wherein the continuous pilot symbols is present at the same sub-carrier locations in the first OFDM symbols and the second OFDM symbols.