Transmitter and method for formatting transmit data into a frame structure

A method implemented in a transmitter, the method comprising:

• formatting transmit data into a frame structure that comprises signal blocks interspersed with training sequences for assisting a receive operation;
• inserting two training sequences between a signal block and its following signal block in the frame structure;
• and
• forming the two training sequences such that a first of the two training sequences is a negative of the second of the two training sequences.

A receiver comprising:

• a receive chain configured to receive data that is formatted into a frame structure that comprises signal blocks interspersed with training sequences for assisting a receive operation;
• a channel estimator configured to estimate what form a training sequence will take when it is received by the receiver;
• and
• a subtractor configured to:
• subtract any part of a training sequence that is predicted by the channel estimator to be included in a received signal block and its adjacent training sequence from that received signal block and its adjacent training sequence to form a subtracted signal block;
• and
• form a padded signal block by zero-padding the subtracted signal block to be twice the length of the transmitted signal block, and output the padded signal block for transforming into the frequency domain.

A method implemented in a receiver, the method comprising:

• receiving data that is formatted into a frame structure that comprises signal blocks interspersed with training sequences for assisting a receive operation;
• estimating, by a channel estimator, what form a training sequence will take when it is received by the receiver;
• subtracting part of a training sequence that is predicted by the channel estimator to be included in a received signal block and its adjacent training sequence from that signal block and its adjacent training sequence to form a subtracted signal block;
• and
• forming a padded signal block by zero-padding the subtracted signal block to be twice the length of the received signal block, and output the padded signal block for transforming into the frequency domain.