For the demand of high speed and massive connections of next-generation mobile communication, improving the total secondary users' transmission rate by the optimization of power allocation in Cognitive Radio-Non-Orthogonal Multi-Access (CR-NOMA) hybrid system was studied, and an algorithm of Power Allocation based on Tabu Search and Q-learning (PATSQ) was proposed. Firstly, the users' power allocation was observed and learnt by the cognitive base station in the system environment, and the secondary users used NOMA to access the authorized channel. Then, the power allocation, channel state and total transmission rate in the power allocation problem were expressed as action, state and reward in the Markov decision process, which was solved by combining tabu search and Q-learning and an optimal tabu Q-table was obtained. Finally, under the constraints of primary and secondary users' Quality of Service (QoS) and maximum transmitting power, optimal power allocation factors were obtained by the cognitive base station by looking up the tabu Q-table, so as to maximize the total transmission rate of secondary users in the system. Simulation results show that under the same total power, the proposed algorithm is superior to Cognitive Mobile Radio Network (CMRN) algorithm, Secondary user First Decode Mode (SFDM) algorithm and the traditional equal power allocation algorithm in terms of the total transmission rate of secondary users and the number of users contained in the system.

A relay selection scheme based on the location of relay node was proposed for the selection problem in a multi-relay cooperative Spatial Modulation (SM) system, and the Bit Error Rate (BER) performance of the system was analyzed. The SM technique was used at the source node by the system, only one transmitting antenna was activated in each time slot, and based on the location information of the relay node, the Amplify Forward (AF) relay closest to the midpoint between the source node and the destination node was selected among all relays in each time slot for forwarding. The approach of moment generating function was used to derive the solution of the pairwise error probability of the system under Rayleigh fading channel, and therefore the theoretical BER of the system was given. Simulation results show that this relay selection method can achieve better BER performance of the system compared with the relay random selection and cyclic forwarding methods.