Patent ID: 6292462
Filing Date: 2001-09-18
Classification: H04L

Abstract:
A method of transmitting signal values comprising generating an output signal which is the sum of:(a) a first signal component which is the product of a first periodic window function and the sum of first carriers and second carriers, the first periodic window function dividing the first signal component into successive first symbol periods, whereinthe first carriers have mutually different frequencies which differ from one another by even integer multiples of a base frequency which is the reciprocal of the symbol period and have a first phase,the second carriers have mutually different frequencies which differ from one another by even integer multiples of the base frequency and differ from the first carriers by odd integer multiples of the base frequency and are in phase quadrature to the first carriers,each of the first and second carriers being modulated during each of the first symbol periods with a respective one of the signal values;(b) a second signal component which is the product of a second periodic window function and the sum of third carriers and fourth carriers, the second periodic window function dividing the second signal component into successive second symbol periods, whereinthe second periodic window function is identical to the first periodic window function but shifted in time by half a symbol period such that the second symbol periods are shifted in time by half a symbol period relative to the first symbol periods,the third carriers have mutually different frequencies which differ from one another by even integer multiples of the base frequency and differ from the first carriers by odd integer multiples of the base frequency and have the first phase, andthe fourth carriers have mutually different frequencies which differ from one another by even integer multiples of the base frequency and differ from the first carriers by zero or even integer multiples of the base frequency and are in phase quadrature to the first carriers,each of the third and fourth carriers being modulated during each of the second symbol periods with a respective one of the signal values.