Carrier frequency estimation method for underlay spectrum sharing time-frequency overlapped MASK signal

Abstract

The invention discloses a carrier frequency estimation method for an underlay spectrum sharing time-frequency overlapped MASK signal. The method comprises the following steps: calculating a diagonal slice spectrum of a cyclic bispectrum of the received time-frequency overlapped MASK signal, and intercepting a f= 0 section; carrying out noise elimination and enhancement on a spectral line by using a minimum optimization algorithm with L0 norm; carrying out segmental windowing on the spectral line, setting a local threshold, and only retaining a discrete spectral line larger than the threshold; calculating a strength mean ratio of the spectral line in each window, searching a local maximum value of the strength mean ratio of the spectral line in each window, counting the local maximum values, and sorting the local maximum values according to size; and obtaining frequency corresponding to the local maximum values according to the size sequence in accordance with the number of time-frequency overlapped signal components, namely carrier frequency of the time-frequency overlapped MASK signal. According to the invention, the estimation performance in an environment with a low signal to noise ratio is good; and in the case that two signals or three signals are overlapped, when the signal to noise is larger than 5dB, the estimation performance of the carrier frequency is better.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to a method for estimating a carrier frequency of a time-frequency overlapping MASK signal under underlay spectrum sharing. Background technique [0002] In the underlay spectrum sharing mode, the primary user shares spectrum with multiple users, thereby improving spectrum utilization. At this time, the primary user and the secondary user completely overlap in the time domain and partially overlap in the frequency domain, and the signals are independent of each other. In underlay cognitive radio, the secondary user can share the spectrum with the primary user without exceeding the interference temperature. The carrier frequency is the main parameter of the interference temperature, so the measurement of the interference temperature requires the estimation of the carrier frequency. [0003] At present, there are few researches on parameter estimation of time-freque...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a carrier frequency estimation method for time-frequency overlapping MASK signals under underlay spectrum sharing, aiming to solve the problems of poor precision and poor applicability in the current parameter estimation methods for time-frequency overlapping signals

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