Suboptimal low-complexity SCMA codebook design method

Abstract

The invention belongs to the field of communication, the invention provides an SCMA codebook design method with good bit error performance. the poor bit error rate performance can be ensured; the complexity of codebook design can be greatly reduced; the invention relates to a suboptimal SCMA codebook design method with low complexity, which comprises the following steps of: 1, dividing a sparse coding multiple access SCMA codebook optimization problem into k sub-problems, constraining the average power of sub-codewords on each problem dimension, and maximizing the minimum Euclidean distance between the sub-superposition codewords at the same time; 2, vectorizing the kth dimension sub-codeword, and expressing the SCMA codebook optimization problem as a quadratic constraint quadratic programming problem; step 3, solving the quadratic constraint quadratic programming problem by using a positive semi-definite relaxation method to obtain a kth dimension sub-code word; and step 4, accordingto the mapping matrix, allocating the sub-code words of all k dimensions to corresponding users to obtain a complete SCMA codebook. The method is mainly applied to SCMA codebook design occasions.

Description

technical field [0001] The invention belongs to the communication field and relates to sparse code division multiple access (SCMA) technology, in particular to a suboptimal low-complexity SCMA codebook design method. Background technique [0002] Driven by the rapid growth of mobile Internet services and Internet of Things services, the fifth-generation mobile communication system must not only greatly improve system spectrum utilization, but also be able to support massive device connections. These requirements have promoted the development of non-orthogonal technology. As a new type of non-orthogonal multiple access technology (NOMA), SCMA superimposes system user information on mutually orthogonal physical layer resources for transmission. There is non-orthogonal interference between users, and the receiving end needs to pass The advanced receiving algorithm separates the information of each user, which not only improves the spectrum efficiency, but also doubles the acces...

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Problems solved by technology

However, these methods cannot clearly solve the codebook, and there is no indication on how to set the rotation angle

Literature [4] proposed a codebook design scheme based on the joint optimization of the constellation diagram and the mapping matrix, but the complexity of the scheme is very high, and it cannot be realized when the number of users or the modulation order is large.

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