Multiuser detection method based on serial strategy for SCMA (Sparse Code Multiple Access) uplink communication system

Abstract

The invention provides a multiuser detection method based on a serial strategy for an SCMA (Sparse Code Multiple Access) uplink communication system, and belongs to the field of signal detection of wireless communication systems. The method is characterized in that nodes in a conventional SCMA factor graph are divided into J groups (J is a quantity of user nodes); each group comprises one user node and all resource nodes connected with the user node; and all nodes (one user node and all the resource nodes which are connected with the user node) of each group are updated in sequence in each iteration process. According to the multiuser detection method, already-updated node messages are utilized in each iteration process, so that a utilization ratio of the already-updated node messages can be effectively increased. The BER (Bit Error Rate) performance of the method is far superior to the BER performance of a method in the prior art under the condition of less iteration times. The calculation complexity of the method is much lower than the calculation complexity of the method in the prior art under the condition of hardly any loss of the BER performance.

Description

technical field [0001] The invention belongs to the field of signal detection of wireless communication systems, and relates to a multi-user detection method of a sparse code multiple access (SCMA) uplink communication system with fast convergence speed and low complexity, specifically a serial strategy-based MPA detection method The method is used to solve the multi-user detection problem of 5G (fifth generation mobile communication) mobile communication alternative multiple access technology. Background technique [0002] Multiple access is one of the core technologies of the physical layer of wireless communication, which enables the base station to distinguish and serve multiple end users at the same time. In order to meet the needs of 5G (fifth generation mobile communication) for large capacity, massive connections, and low-latency access, the invention patent "System and method for user sparse code multiple access" with application number 201380059380. A SCMA (Sparse...

AI Technical Summary

Problems solved by technology

However, in practical engineering applications, as the number of iterations increases, the hardware calculation complexity of the communication system is getting higher and higher, so the hardware requirements are also getting higher and higher; and in this method, all resource nodes to user node messages renew is the message from the user node to the resource node obtained based on the t-1th iteration Update of all user node to resource node messages is updated based on the current iteration Although Make good use of the current iterative update but is generated based on the previous iteration The update message from the user node to the resource node in the current iteration is not utilized, resulting in a low convergence rate

In summary, although the above parallel MPA detection method can effectively improve the probability of correct decoding, it cannot meet the high-speed and high-efficiency requirements of 5G due to its high computational complexity and low convergence rate.

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