Research On Sum-rate Maximization Algorithm For Millimeter Wave Hybrid Precoding Communication Systems

Millimeter wave(mm Wave)is treated as a reliable solution for 5th generation and post 5th generation wireless communication(5G and B5G)networks due to its abundant spectrum resources,which can achieve ultra-high rate data transmission in the Gbit/s range.However,with such a high frequency band,mm Wave communication is bound to bring huge transmission attenuation and water molecule absorption loss,which will greatly affect its transmission distance and coverage.At the same time,the corresponding wavelength will become shorter due to the significant increase in mm Wave frequency,leading to the miniaturization and integration of massive antenna arrays at both the transceiver and transmitter ends of the deployment becomes possible.However,massive MIMO technology for mm Wave communications brings new scientific challenges,including two aspects: firstly,the hardware complexity of beamforming(BF): the dramatically increased array size of massive MIMO makes it impractical for each array element to connect to a separate RF chain architecture,and the formation of directional beams also has a very high computational complexity;secondlly,the time Overhead problem: the establishment of Access Point(AP)to connect the user directional beam link has high requirements for the integrity of the CSI,directly in the massive MIMO array using traditional MIMO systems channel estimation techniques will bring huge estimation overhead;this overhead in the consideration of user distribution randomness and mobility will not be tolerated,resulting in the overall transmission performance deterioration or even communication link cannot be maintained.Based on the above complexity and overhead problems of BF,complete acquisition of CSI at the receiver side becomes impractical for application to BF.The mm Wave communication systems has some urgent scientific challenges in the areas of low-complexity BF and low-overhead BF: low-complexity,high-performance multi-resolution codebook construction method with resolution structure;low-overhead,high-reliability BF maximization and Sum-Rate(SR)solution.Finding the optimal communication transceiver BF vector pairs in pre-designed codebooks combined with low-complexity BF algorithms can effectively solve these challenges.On the one hand,the fixed codebook-based mm Wave communication systems does not need to obtain the CSI of transceiver,which solves the huge estimation overhead and feedback overhead caused by channel estimation;on the other hand,its simplified search principle,combined with the low-complexity hybrid BF search algorithm,greatly reduces the energy cost and time complexity of the systems.This paper intends to develop the design of the maximized SR algorithm for BF technique under hybrid precoding structure of mm Wave communication systems based on the designed fixed multi-resolution hierarchical codebook by synthesizing the above two scientific challenges,and the main research includes the following two aspects:(1)Firstly,the complete multi-resolution codebook design technique is systematically studied in the framework of mm Wave communication systems incorporating massive MIMO technology,which will provide a complete set of multi-resolution codebook design methods for the fully connected hybrid precoding structure of mm Wave communication systems under the condition of limited Radio Frequency(RF)chain resources,making the joint design of adaptive BF and transceiver-transmitter possible,and laying the necessary foundation for the subsequent research and design of SR maximization algorithm based on the low-complexity hybrid BF technology with fixed codebook.(2)Secondly,for multi-user scenarios,a key factor that causes SR variation in mm Wave communication systems is its interference plus noise.Based on this,this paper proposes to design an improved low-complexity Hybrid Beamforming Grouping Sum-Rate Maximization(HBG-SRM)algorithm for maximizing the SR of the mm Wave communication systems under the premise that both the base station and the user side adopt the hybrid precoding BF architecture and the downlink channel is the ideal channel.SR for mm Wave hybrid precoding communication systems,which provides a low-complexity,low-overhead,high-reliability and efficient solution for BF in the hybrid precoding structure of mm Wave communication systems.