Transmitter with a variable sampling rate

摘要

The present invention presents a method and a system for mitigating effects of clock harmonics in the receiver. The receiving signal may be monitored in such a way that the interfering harmonic component is tracked. When the interfering frequency is found out, the system determines the clock or clocks in the transceiver which are contributing to the interfering spurious tone. After that, the contributing clock(s) frequency is selected so that the effect of the spurious tone in the receiving passband is minimized or mitigated. This is performed by selecting a suitable clock frequency resulting in the spurious tones all falling outside the receiver passband; or in an OFDM system, by choosing a clock frequency deriving the spurious tone straight onto a subcarrier signal frequency.

主权项

1. A method for mitigating effects of spurious tones caused by clock signals in a transceiver, comprising a transmitter and a receiver, the method comprising:
determining at least one clock signal which contributes to a creation of at least one spurious tone on a receiver signal path, at least one determined clock signal relating to at least one of an analog-digital converter, a digital-analog converter and a sample rate converter of the transceiver; measuring a spectrum of a received signal on the receiver signal path; and if detecting a spurious tone in the spectrum, selecting a frequency for the determined clock signal based on the detected spurious tone to mitigate the effect of spurious tones in operation of the receiver, wherein the detecting of the spurious tone comprises detecting an increase in power spectral density at a frequency that falls substantially on a multiple of a the frequency of for the determined clock signal.