A Simplified Implementation Method of Parallel Constant Modulus Algorithm Applicable to Coherent Optical Communication System

Abstract

The invention discloses a parallel CMA simplified implementation method applicable to a coherent light communication system, and relates to the field of coherent light communication systems. Aiming at an L-path parallel computing structure, an N-order self-adapting filter uses a same filter coefficient set to compute parallel output data corresponding to L-path parallel input data, wherein N is not more than L; and therefore, the N-order filter coefficient is updated once per L pieces of input data. The update amount of the filter coefficient is proportional to the product of an error function, output data and corresponding input data conjugation; one of the L paths of output data is selected to compute the value of the error function, the obtained value is multiplied by the output data and further multiplied by the corresponding input data conjugation, for replacing the multiplying of all L paths of output data, the corresponding error function and the corresponding input data conjugation, and then summation is performed, and thereby the computation quantity for updating the filter coefficient is saved. According to the method, logic units needed by achieving a load-balancing algorithm are greatly decreased, and the computation complexity is reduced.

Description

technical field [0001] The invention relates to the field of coherent optical communication systems, in particular to a simplified implementation method of a parallel constant modulus algorithm suitable for coherent optical communication systems. Background technique [0002] With the rapid development of network communication technology, polarization multiplexing coherent optical communication system is widely used in various long-distance and backbone network transmission systems. However, while increasing the channel capacity and increasing the transmission rate, factors such as power attenuation, dispersion, and nonlinear effects have become bottlenecks restricting the development of optical communication, and the system's requirements for dispersion compensation have greatly increased. [0003] In order to overcome the negative effects brought by various dispersion losses in the transmission system, various equalization algorithms are usually used to compensate. Among ...

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Problems solved by technology

[0016] Due to the high rate of related optical communication, the digital processing at the receiving end needs to use a parallel processing structure. If it is implemented in FPGA (Field-Programmable Gate Array, Field-Programmable Gate Array) according to the above CMA theoretical formula, it will take more time. The pipeline structure of extension unit and multi-stage filter requires more logic units, and the complexity of realizing the equalization algorithm is relatively large

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