KDE non-uniform quantization method of multicarrier modulation optical communication system based on filter bank

Abstract

The invention relates to a KDE non-uniform quantization method of a multicarrier modulation optical communication system based on a filter bank. The method comprises the following steps: (1) carrying out amplitude limiting operation on a signal at different amplitude limiting ratios; (2) initializing a bandwidth and a kernel function according to signal distribution characteristics and non-parametric kernel density estimation requirements; (3) using a kernel function as a distribution function of each data point; (4) linearly superposing the distribution functions of all representative data points to obtain a distribution curve of a fitting signal; (5) normalizing the distribution curve of the fitting signal to obtain a fitting signal probability density function; (6) solving an optimal quantization level combination under the minimum quantization error constraint for the fitting signal probability density function by using nonlinear programming; and (7) quantizing the input signal according to the optimal quantization level combination. According to the KDE non-uniform quantization method, the bit error rate is lower during signal transmission, and better system quantization performance is achieved.

Description

technical field [0001] The invention belongs to the technical field of optical communication, and in particular relates to a KDE non-uniform quantization method of a multi-carrier modulation optical communication system based on a filter bank. Background technique [0002] In recent years, with the development of artificial intelligence, big data, cloud computing and other technologies, people's demand for access bandwidth is also growing rapidly year by year. Multi-carrier modulation technology is widely used in optical access network systems based on IMDD because of its advantages in meeting high capacity, asynchronous transmission and spectral efficiency. At the same time, multi-carrier modulation technology is one of the current research hotspots of 5G key technologies because of its advantages such as high spectral efficiency and anti-multipath interference. The traditional multi-carrier modulation technology (OFDM) wastes spectrum resources due to the introduction of ...

AI Technical Summary

Problems solved by technology

Although this method improves the transmission performance of the system, the quantization effect in the IMDD-UFMC system is not good

In the IMDD filter bank multi-carrier system, after the waveform is processed by the filter, the waveform distribution presents a peak at the mean value of zero and upward instead of a Gaussian distribution, so the quantization scheme based on the Gaussian distribution cannot fit the waveform distribution.

Because the non-uniform quantization scheme based on Gaussian distribution cannot reflect the characteristics of UFMC that small signals account for the majority, there is a problem of insufficient fitting accuracy, resulting in poor matching between the optimal quantization level and the signal, resulting in large quantization errors

In summary, there is still room for improvement in the quantization-order optimization algorithm

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