A Non-data-aided Blind Phase Noise Estimation Method for QAM Signals

A non-data-assisted, phase-noise technology, applied in digital transmission systems, baseband system components, multi-carrier systems, etc., can solve problems such as no closed-form solution of the algorithm, difficult real-time processing, and large amount of calculation, and achieve simplification of the estimation process , good estimation performance, and the effect of reducing computational complexity

CN105933265BActive Publication Date: 2019-04-23QUANZHOU INST OF EQUIP MFG
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2019-04-23

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Abstract

The invention relates to a non-data aided phase noise blind estimation method for QAM signal, an M-th power algorithm based on improvement is provided, the algorithm can correct the frequency deviation and the phase deviation caused by the phase noise, a power estimation algorithm is adopted without any other data information for the frequency deviation and the phase deviation in the signal, a more precise output information is obtained through gradually correcting the estimation error, the estimation process is simplified, and the computation complexity is greatly reduced; according to the invention, in a condition that has no need to have the help of signal-to-noise ratio and auxiliary data information, the method represents good estimation performance, and a simple and efficient solution is provided for the high-speed wireless optical communication QAM signal phase estimation problem.
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Description

technical field

[0001] The invention belongs to the field of wireless optical communication, and relates to the phase noise estimation and compensation problem of high-speed wireless optical communication, in particular to a non-data-assisted phase noise blind estimation method for QAM signals. Background technique

[0002] In visible light communication, due to the complex channel and noise distribution, the performance of basic modulation methods is not ideal. Some efficient modulation methods such as QAM (Quadrature Amplitude Modulation, Quadrature Amplitude Modulation) have been attracting attention.

[0003] For any carrier signal modulated by a digital signal, the transmission process has a certain carrier frequency band. Therefore, at the sending end, the digital-to-analog converted signal is modulated to a certain frequency and reaches the signal receiving end through the propagation medium. When the signal receiving end demodulates, the signal is down-converted firs...

Examples

Embodiment Construction

[0036] For the QAM signal demodulation system, the received RF signal is processed by matched filtering, analog-to-digital conversion, and timing recovery frequency offset compensation to obtain a received signal containing carrier phase noise r n :

[0037]

[0038] In formula (1), d n To send a signal, f e is the carrier frequency offset value, T is the symbol period, v n is periodic complex Gaussian stationary noise, and r n Statistically independent, θ is the phase deviation value, n=1,2,...,N, N represents the total number of received signal samples; in formula (1) because f e The existence of and θ will seriously affect the received signal, making it impossible to make a decision. to eliminate f e and θ interference, these two parameters must be estimated, and then the signal is compensated according to the estimated value, thereby eliminating the influence.

[0039] The demodulation of the QAM signal receiving end is as follows: figure 1 As shown, r(t) is the tr...