Transmitters, receivers and methods of transmitting and receiving

A receiver configured to recover data from Orthogonal Frequency Division Multiplexed (OFDM) symbols, the OFDM symbols including a plurality of sub-carrier signals, some of the sub-carrier signals carrying data and some of the sub-carrier signals carrying pilots, the pilots comprising continual pilots, the continual pilots being distributed across the sub-carrier signals in accordance with a continual pilot pattern selected from a plurality of continual pilot patterns including a first continual pilot pattern and at least one second continual pilot pattern derived from the first continual pilot pattern, the receiver comprising:

• a demodulator configured to detect a signal representing the OFDM symbols and to generate a digital version of the OFDM symbols in a time domain;
• a 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 sub-carrier signals carrying pilots and the sub-carrier signals carrying data can be recovered;
• and
• a detector configured to:
• determine a number of sub-carrier signals in the plurality of sub-carrier signals,
• determine the continual pilot pattern of the OFDM symbols based on the number of sub-carrier signals, and
• recover the data and the pilots from the sub-carrier signals.

A method for recovering data from Orthogonal Frequency Division Multiplexed (OFDM) symbols, the OFDM symbols including a plurality of sub-carrier signals, some of the sub-carrier signals carrying data and some of the sub-carrier signals carrying pilots, the pilots comprising continual pilots, the continual pilots being distributed across the sub-carrier signals in accordance with a continual pilot pattern selected from a plurality of continual pilot patterns including a first continual pilot pattern and at least one second continual pilot pattern derived from the first continual pilot pattern, the method comprising:

• detecting a signal representing the OFDM symbols;
• generating a digital version of the OFDM symbols in a time domain,
• receiving the time domain digital version of the OFDM symbols and forming a frequency domain version of the OFDM symbols, from which the sub-carrier signals carrying pilots and the sub-carrier signals carrying data can be recovered,
• determining a number of sub-carrier signals in the plurality of sub-carrier signals;
• determining the continual pilot pattern of the OFDM symbols based on the number of sub-carrier signals;
• and
• recovering the data and the pilots from the sub-carrier signals.