US 2009/0022248 A1 · Method for Demodulating the Signal of Multiple-Position Frequency Manipulation with Equidistant Frequency Spreading, Demodulator for this Signal, and Computer-Readable Medium

Abstract

This invention relates to signal transmitting engineering. The use of the inventive method demodulation of a signal of multiple position frequency manipulation with equidistant frequency spreading allows to reduce the threshold of demodulation and to ensure a quality of demodulation, which is at least identical to that of a quasi-optimal demodulator. To obtain such a result, a frequency grid is formed with a possibility of precise tuning of frequency spreading; during the reception, values having a maximum module of reception signal are extracted at all frequencies switchable values at clock frequency, this clock frequency is extracted from maximum of the received signals and is used for a precise tuning of the frequency spreading; a grid of tunable frequency is tuned with a precisely tuned frequency spreading for exact values of a frequency of received signal, and demodulation is effected by the way of coherent reception of the received signal, using only one from quadrature signals to decide whether a signal of a determined frequency is absent or present among the mentioned exact values of frequency.

Claims10

Dependent claims

A method for demodulating a signal of multiple frequency manipulation with equidistant frequency spreading, comprising:

forming an array of adjustable frequencies from f1 to fm for exact adjusting of said frequency spreading, where m is a maximum number of the frequencies in the signal of multiple frequency manipulation with equidistant frequency spreading fp=kft, where ft is a clock frequency, k=1, 2, . . . , an initial frequency values in the array being allocated in such regions, where exact values of a frequency of a received signal could be situated;
demodulating the received signal using the array;
while receiving the received signal, extracting maximum values in modulus of the received signal on all frequencies fi (i=1, . . . , m) switched with the clock frequency ft to obtain switched maximum values;
extracting the clock frequency ft from the switched maximum values of the received signal for exact adjusting the frequency spreading fp to the clock frequency ft;
tuning the array of adjustable frequencies with the frequency spreading adjusted to the exact values of the received signal frequency;
wherein demodulating the received signal occurs by coherently receiving the received signal using only one of the quadrature channels for ascertaining the presence or absence of a signal of a particular frequency from said exact frequency values.

3 more elements

A demodulator for a signal of multiple frequency manipulation with equidistant frequency spreading, comprising:

m quadrature channels, wherein m is a maximum number of quadrature frequencies in the signal of multiple frequency manipulation with the equidistant frequency spreading;
a frequency former, wherein each of m outputs is connected to a reference input of a respective quadrature channel;
a decision unit for making a decision on the presence or absence of a signal with a particular frequency in the signal of multiple frequency manipulation, wherein outputs of said decision unit are demodulator outputs;
m modulus calculators, which information inputs are the united input of the demodulator;
a maximum in modulus selection unit, which every input being connected to the output of respective value in modulus calculator;
a first and second commutators, which control inputs are connected to the first output of said maximum in modulus selection unit, and which outputs are connected to the first and second inputs of said frequency former;
a clock-frequency discriminator, which input is connected to the second output of said maximum in modulus selection unit, and which output is connected to the third input of said frequency former;
the first output of each quadrature channel is connected to the first input of the respective value in modulus calculator and respective information input of the first commutator;
the second output of each quadrature channel is connected to the second input of the respective value in modulus calculator, respective information input of the second commutator, and respective input of the decision unit;
said frequency former being configured for forming an array of m frequencies adjusted according to the output signals from said commutators, with the equidistant frequency spreading adjusted according to the output signal of said clock frequency discriminator, the first to m-th outputs of the frequency former being connected to the reference inputs of the first to m-th quadrature channels, respectively.

7 more elements

Dependencies are inferred from the claim text.

Method for Demodulating the Signal of Multiple-Position Frequency Manipulation with Equidistant Frequency Spreading, Demodulator for this Signal, and Computer-Readable Medium

Life of this patent

Method for Demodulating the Signal of Multiple-Position Frequency Manipulation with Equidistant Frequency Spreading, Demodulator for this Signal, and Computer-Readable Medium

Life of this patent

Abstract

Claims10