Patent ID: 6628927
Filing Date: 2003-09-30
Classification: H03D,H04B

Abstract:
A method for transmitting a modulation signal in a multiple channel radio system, in which each channel has an associated channel frequency and the channel frequencies of adjacent channels are separated by a channel spacing, the method comprising the steps of:selecting, by means of a switch, one of said multiple channels, a selected one of said channels providing a radio frequency output signal at a channel frequency of the multiple channel radio system; a first processing step of processing the modulation signal in combination with a first analogue modulating signal to produce an analogue intermediate signal, and a second processing step of processing the analogue intermediate signal in combination with a second analogue modulating signal to produce said radio frequency output signal at said channel frequency of the multiple channel radio system, wherein said second processing step includes an offsetting of the frequency in at least one of said multiple channels at a circuit point following said switch with reference to a direction of signal flow in said selected channel, wherein the frequency resolution of the second analogue modulating signal is wider than the channel spacing, and the frequency resolution of the first analogue modulating signal is finer than the frequency resolution of the second analogue modulating signal, and the frequencies of the first and second analogue modulating signals are adjusted in accordance with their respective frequency resolutions so as to change the channel frequency of the output signal.