CR-NOMA bidirectional relay self-interference energy recovery and transmission method

Abstract

The invention discloses a CR-NOMA bidirectional relay self-interference energy recovery and transmission method. The method comprises the following steps: firstly, secondary user transmission is assisted in a CR-NOMA system through a bidirectional relay; meanwhile, under the constraint conditions that relay energy capture is limited and the like, the weak user physical layer safety rate is maximized, the weak user physical layer safety rate is converted into a convex problem according to a semi-definite relaxation theory, a method for jointly optimizing a signal covariance matrix and power distribution factors sent and received by the relay through an iterative algorithm is introduced, and finally a globally optimal solution of the weak user physical layer safety rate is obtained. According to the invention, the weak user physical layer security rate is improved.

Description

technical field [0001] The invention belongs to the field of wireless communication, in particular to a CR-NOMA two-way relay self-interference energy recovery transmission method. Background technique [0002] With the development of wireless communication technology, the demand for wireless spectrum resources continues to increase, but the actual measurement results show that the utilization rate of a large number of licensed spectrum is very low. In order to improve the utilization rate of spectrum, cognitive radio is a key technology to improve spectrum utilization rate. At the same time, non-orthogonal multiple access (NOMA) is widely used in the process of multi-user transmission as another technology to improve spectrum efficiency. Therefore, cognitive radio (CR) and non-orthogonal multiple access technology are two As a key technology to improve spectrum efficiency, the combination of the two has been widely concerned. [0003] However, in the signal transmission pr...

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Problems solved by technology

[0002] With the development of wireless communication technology, the demand for wireless spectrum resources continues to increase, but the actual measurement results show that the utilization rate of a large number of licensed spectrum is very low. In order to improve the utilization rate of spectrum, cognitive radio is a key technology to improve spectrum utilization rate. At the same time, non-orthogonal multiple access (NOMA) is widely used in the process of multi-user transmission as another technology to improve spectrum efficiency. Therefore, cognitive radio (CR) and non-orthogonal multiple access technology are two The combination of these and others has been widely concerned as a key technology to improve spectral efficiency

[0003] However, cognitive radio and non-orthogonal multiple access (CR-NOMA) systems have two problems to be solved in the signal transmission process. On the one hand, in order to ensure the quality of service of the primary user in the CR-NOMA system, the transmission power of the secondary user is limited. limited, so that its long-distance transmission is affected, and the secondary user's transmission performance can be effectively improved by assisting the secondary user's transmission through cooperative relay

On the other hand, NOMA is easily interfered by the same frequency channel during the transmission process, so long-distance transmission is difficult to guarantee, and the transmission rate is reduced. Therefore, combining cognitive radio with NOMA can improve frequency utilization and security rate.

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