SCMA decoder based on probability calculation

Abstract

The invention discloses an SCMA decoder based on probability calculation. The SCMA decoder is characterized by comprising an initialization module, an observation node updating module, a variable node updating module and a likelihood ratio calculation module; the initialization module is connected to the observation node updating module and used for initializing a channel parameter and calculating the joint condition probability of all codewords possibly sent by a user born by each resource block; the observation node updating module is connected to the variable node updating module and used for calculating the edge condition probability according to the joint condition probability; the variable node updating module is connected to the likelihood ratio calculation module and used for calculating the posterior probability according to the edge condition probability, normalizing the posterior probability and returning the normalized posterior probability to the observation node updating module; and the likelihood ratio calculation module is used for calculating and outputting likelihood information according to the posterior probability. The SCMA decoder disclosed by the invention is low in area overhead and high in system throughput and calculation efficiency.

Description

technical field [0001] The invention relates to the field of wireless communication, in particular to an SCMA decoder based on probability calculation. Background technique [0002] SCMA (Sparse Code Multiple Access) technology is an alternative multiple access technology designed for 5G requirements such as large capacity, massive connections, and ultra-low latency. At the sending end, it directly maps the coded bits to multi-dimensional codewords in the complex domain, and the codewords of different users are non-orthogonally superimposed on the same resource block in a sparse spreading manner; the receiving end uses sparsity for low-complexity Multi-user joint detection. Compared with OFDMA technology, SCMA uses non-orthogonal superposition to serve more users at the same time under the same amount of resources, thereby effectively improving the overall system capacity. [0003] MPA (Message Passing Algorithm) iterative decoding algorithm is proved to be the optimal dec...

AI Technical Summary

Problems solved by technology

However, the hardware complexity corresponding to the Max-logMPA algorithm is still high, and when applied to the 5G communication scenario with massive connections, the area overhead is large, the system throughput rate is low, and the calculation efficiency is low

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