Identification method of low signal-to-noise ratio phase-shift keying modulating signal

Abstract

The invention discloses an identification method of a low signal-to-noise ratio phase-shift keying modulating signal, which belongs to the technical field of communication. The identification method of the low signal-to-noise ratio phase-shift keying modulating signal firstly identifies a BPSK signal through a quadratic spectrum based on dislocation multiplication, then identifies a QPSK or OQPSKsignal through a biquadrate spectrum based on dislocation multiplication, and then calculates an envelope spectrum and implements optimization processing, and finally identifies the QPSK signal and the OQPSK signal through the optimized envelope spectrum. The invention provides a quadratic or biquadrate amplitude spectrum function calculation mode based on dislocation multiplication, which can effectively reduce the interference of noise to signal, thus effectively improving the recognition rate of the phase-shift keying modulating signal under the condition of lower signal-to-noise ratio; inaddition, the optimized biquadrate amplitude spectrum and envelope spectrum are adopted to further reduce the negative influences on spectrum peak searching caused by noise, thereby effectively improving the recognition rate. A simulation result indicates that the identification method of the low signal-to-noise ratio phase-shift keying modulating signal can realize recognition rate of more than 90 percent between QPSK and OQPSK when the signal-to-noise ratio is 0 dB; and the recognition rate between QPSK and BPSK can reach more than 90 percent when the signal-to-noise ratio is -7dB.

Description

Technical field: [0001] The invention belongs to the technical field of communication, and relates to an automatic identification method of a phase-shift keying (PSK) signal modulation mode under the condition of a relatively low signal-to-noise ratio. Background technique: [0002] Today is an era of information technology changing with each passing day. Various communication methods and communication technologies emerge in an endless stream, making our living space full of various electromagnetic waves. In traditional communication stations or systems, once the transmitting and receiving parties are turned on, they work in a fixed modulation mode. Today's communication methods, such as software radio, show the characteristics of multi-system, multi-band, multi-rate, and multi-service, which makes it impossible for the communication receiver to wait and receive on a specific modulation method unless it is agreed in advance. Especially for the software radio station used as...

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Problems solved by technology

[0017] The present invention aims at the problem that the identification rate of the existing phase-shift keying modulation signal identification method decreases or fails under the condition of low signal-to-noise ratio, and proposes a new identification method of phase-shift keying modulation signal with low signal-to-noise ratio. A calculation method based on the dislocation multiplication of the quadratic or quartic magnitude spectrum function proposed by the present invention is carried out, and the quadratic magnitude spectrum function and the envelope spectrum are optimized, which can realize the phase under the condition of low signal-to-noise ratio Effective Identification of Modulated Signals by Shift Keying Signals

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