Method of pseudo uniform quantization in multi-user spectrum sensing

Abstract

The invention discloses a method of pseudo uniform quantization in multi-user spectrum sensing and mainly solves the problem that the existing quantization method for multi-user spectrum sensing is high in computation cost. The method includes the steps of firstly, allowing sensing users to report an average and a variance in test statistics to a fusion center; secondly, allowing the fusion center to determine quantization level and the number of sensing users first and then calculating a probability mass function of the test statistics and surrounding area of a ROC (receiver operating characteristic) curve; thirdly, establishing a mathematical programming problem according to the area, solving the mathematical programming problem to obtain a quantization threshold epsilon i; and fourthly, allowing the fusion center to issue the quantization threshold epsilon i to the i-th sensing user, and allowing each sensing user to quantize the test statistics according to the obtained quantization threshold. The method has the advantages of excellent performance and low cost, and is applicable to quantization of the test statistics by any types of detectors in multi-user spectrum sensing.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, relates to quantization technology, in particular to a pseudo-uniform quantization method in multi-user spectrum sensing, which can be used in multi-user spectrum sensing in a cognitive radio system. Background technique [0002] With the rapid development of wireless and mobile communications, the contradiction between the increasing demand for wireless spectrum and the limited spectrum resources has become a prominent contradiction in the current wireless communication industry. The phenomenon of extremely low utilization rate. In order to improve the status quo of low spectrum utilization, J.Mitola et al. proposed the concept of cognitive radio. The main idea is to find idle spectrum in the licensed frequency band and allow cognitive Users can perceive, identify and access the currently idle frequency band, thereby greatly improving spectrum utilization. In order to make full ...

AI Technical Summary

Problems solved by technology

In the uniform quantization method, the quantization level value and the quantization threshold are easier to obtain, and the calculation overhead is lower, but because the characteristics of the signal itself in practical applications are not considered, it shows poor sensing performance in cooperative spectrum sensing

Although the Lloyd-Max quantization method combines the distribution characteristics of the signal itself to make the cooperative spectrum sensing system have better sensing performance, but this method is based on the logarithmic likelihood ratio LLR or likelihood ratio LR domain for quantization, and in fact The probability density function of the LLR domain is not available in some applications, which requires quantization methods that can be applied to other domains

In addition, when the number of cooperative cognitive users or the number of quantization levels of each user increases, the computational overhead of the Lloyd-Max quantization method will increase rapidly when estimating the false alarm probability and detection probability

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