US 2007/0263701 A1 · Code Nco and Gps Receiver

Abstract

A code NCO is provided which correctly outputs a predetermined code enable signal by executing a simple control, depending on a frequency of a clock signal, with an optimal circuit scale. A multiplexer 1 receives integers of N and M which are relatively prime, and outputs either of them to an adder 2, depending on an output signal of a comparator 6. The adder 2 adds an integer latched by the register 5 and an integer output by the multiplexer 1, and outputs the result via a multiplexer 4 to the register 5. The register 5 latches and outputs the received integer to the comparator 6 with a frequency fs of a sampling clock signal SCLK. In accordance with a threshold set based on the integers of N and M and the number L of bits of the adder 2 or the register 5, the comparator 6 outputs a signal having the High state only when the output integer of the register 5 satisfies the threshold condition. The code NCO outputs this signal as a code enable signal having a frequency fo.

Claims10

Dependent claims

A code NCO for generating a code enable signal for code phase observation, comprising:

a first multiplexer which is configured to receive two relatively prime integers, and to feed either of the two integers as a first integer output in accordance with a select signal;
an adder which is configured to add the first integer output from the first multiplexer and an integer output from a register in order to feed a second integer output;
a second multiplexer which is configured to receive the second integer output from the adder and a code phase adjustment value, and to feed either of them as a third integer output based on an adjustment signal;
the register which is configured to latch and to feed the third integer output from the second multiplexer as a fourth integer output in accordance with a sampling clock signal;
and
a select signal generator which is configured to output the select signal when the select signal generator detects that the fourth integer output from the register is a predetermined integer value which is previously set,
wherein the select signal is the code enable signal.

4 more elements

Dependencies are inferred from the claim text.

Code Nco and Gps Receiver

Life of this patent

Code Nco and Gps Receiver

Life of this patent

Abstract

Claims10