Digital radios

摘要

A digital radio receiver comprises:
a first section arranged to receive an analog radio signal and to generate therefrom digital intermediate frequency I and Q channel samples,a second section arranged to convert said I and Q channel samples to a lower, baseband frequency, said second section comprising:
a first coordinate rotation digital computer module arranged to perform a complex rotation of the I channel samples;a second coordinate rotation digital computer module arranged to perform a complex rotation of the Q channel samples;a phase accumulator arranged to provide an output signal representing a complex rotation to be applied to each of the I and Q channel samples,wherein the second section is arranged such that the phase accumulator output signal is modified by a phase offset signal prior to being supplied to one of the first and second coordinate rotation digital computers.

主权项

1. A digital radio receiver comprising:
a first section arranged to receive an analogue radio signal and to generate therefrom digital intermediate frequency I and Q channel samples, a second section arranged to convert said I and Q channel samples to a lower, baseband frequency, said second section comprising:
a first coordinate rotation digital computer module arranged to perform a complex rotation of the I channel samples;a second coordinate rotation digital computer module arranged to perform a complex rotation of the Q channel samples;a phase accumulator arranged to provide an output signal representing a complex rotation to be applied to each of the I and Q channel samples, wherein the second section is arranged such that the phase accumulator output signal is modified by a phase offset signal that provides a net difference in the complex rotation which the first and second coordinate rotation digital computer modules are directed to apply prior to being supplied to one of the first and second coordinate rotation digital computer modules.