Patent ID: 6650150
Filing Date: 2003-11-18
Classification: G01S,G06F,H04B

Abstract:
A numerically controlled oscillator for a radio-frequency signal receiver,said oscillator forming part of a pseudo-random code replica generating loop of a radio-frequency signal receiver, said code being representative of a transmitting satellite, the oscillator receiving at one input a clock signal, with a first frequency which clocks operations of the oscillator, and a binary word of several bits, and the oscillator also providing at one output at least an output signal with a frequency determined as a function of said binary word and the clock signal, wherein said oscillator comprises a first accumulation stage, for a first number of most-significant bits of the binary word, and a second accumulation stage for a second number of least-significant bits of said binary word, the first accumulation stage being clocked at the first clock frequency to supply the determined frequency output signal, while the second stage is clocked at a second clock frequency N times lower than the first clock frequency, a certain number of output bits or binary signals from the second stage being introduced at an input of the first stage every N cycles of the clock signal at the first frequency, and wherein a first input register of the first accumulation stage stores the first most-significant bit number of the binary word which defines a code phase offset, wherein a second input register of the second accumulation stage stores the second number of least-significant bits of said binary word, and wherein the first accumulation stage provides at one output a code clock signal for a pseudo-random code generator as a function of said binary word and the first clock frequency.