US 2007/0165748 A1 · Low if radio receiver

Abstract

A slot-based low Intermediate Frequency (‘IF’) radio receiver comprises an IF local oscillator for producing I and Q IF local oscillator signal components in phase quadrature, I and Q mixer channels for mixing the input signal with the I and Q IF local oscillator signal components to produce I and Q IF signal components. The IF local oscillator includes frequency alternation means for causing the IF local oscillator frequency to alternate a plurality of times during each frame between first and second values, one of which is greater and the other smaller than the desired carrier frequency of the input signal so as to reduce the effect of adjacent and alternate interferers. The phase of the baseband local oscillator is alternated in synchronism with the alternation of the IF local oscillator frequency.

Claims14

Dependent claims

A low Intermediate Frequency (‘IF’) radio receiver comprising:

antenna means for receiving a slot-based radio signal comprising successive frames each comprising a set of reception time slots;
input means responsive to a signal from said antenna means for producing an input signal;
local oscillator means for producing at least one local oscillator signal having a local oscillator frequency;
mixer means for mixing said input signal with said local oscillator signal and producing an IF signal;
and
filter means responsive to said IF signal for selectively passing frequencies within a low IF range and rejecting frequencies outside said low IF range so as to produce a filtered signal characterised in that said local oscillator means includes frequency alternation means for causing said local oscillator frequency to alternate a plurality of times during said reception time slots of each of said frames between first and second values one of which is greater and the other smaller than the desired carrier frequency of the input signal.

3 more elements

A low Intermediate Frequency (‘IF’) radio receiver comprising:

an antenna for receiving a slot-based radio signal comprising successive frames each comprising a set of reception time slots;
an input responsive to a signal from said antenna for producing an input signal;
a local oscillator for producing at least one local oscillator signal having a local oscillator frequency;
a mixer for mixing said input signal with said local oscillator signal and producing an IF signal;
and
a filter responsive to said IF signal for selectively passing frequencies within a low IF range and rejecting frequencies outside said low IF range so as to produce a filtered signal characterised in that said local oscillator includes frequency alternation circuit for causing said local oscillator frequency to alternate a plurality of times during said reception time slots of each of said frames between first and second values one of which is greater and the other smaller than the desired carrier frequency of the input signal.

3 more elements

Dependencies are inferred from the claim text.

Low if radio receiver

Life of this patent

Low if radio receiver

Life of this patent

Abstract

Claims14