Patent ID: 8873366

Claim:
A transmitter operable to: receive a group of bits as input and perform at least one inverse Fourier transform on said group of bits to produce orthogonal frequency division multiplex (OFDM) symbols, the inverse Fourier transform having a period of a time T; generate a first OFDM symbol and a second OFDM symbol from the OFDM symbols, wherein: the first OFDM symbol is expressed by superpositions of a set of sub-carriers which are orthogonal over the time T, a duration of the first OFDM symbol is T and the first OFDM symbol is associated with a first guard time having a length of T G ; and the second OFDM symbol is expressed by superpositions of the same set of sub-carriers used to express the first OFDM symbol, the second OFDM symbol is the next OFDM symbol after or the previous OFDM symbol before the first OFDM symbol in a sequence of OFDM symbols, and the duration of the second OFDM symbol is KT and the second OFDM symbol is associated with a second guard time having a length of KT G , where K is a positive integer greater than one; and select a first output from the generated OFDM symbols, the first output having a duration of T plus T G , the first output comprising the first OFDM symbol and a first cyclic prefix of length T G ; and select a second output from the generated OFDM symbols, the second output having a duration of KT plus KT G , the second output comprising the second OFDM symbol and a second cyclic prefix of length KT G .