Maximum Energy Efficiency Scheme Of MU MIMO Wireless Data And Power Transmission System Based On Limited Feedback

At present,with the development of wireless communication technology,multi antenna system,that is,multi input multi output(MIMO)system,has become the key point of development.The advantage of MIMO system and the former single antenna system is that it can send more information without changing the bandwidth of the occupied frequency band,and the effectiveness of the system has been improved.According to the number of users,it can be divided into single user MIMO and multi-user MIMO.The biggest difference is the use of time-frequency resources.In single user MIMO,each antenna occupies different time-frequency resources.By using space division multiplexing technology,multi-user MIMO uses the same time-frequency resources.Compared with the two methods,multi-user MIMO has more advantages,so in real life,multi-user MIMO has become a hot research direction.Since the idea of the Internet of things was put forward,the data transmission device with passive terminal has attracted the interest of many research institutions.Only on the basis of the wireless transmission energy received by the base station,the energy can be stored,and the energy obtained can be used to get the power of the transmission signal,then the forward data transmission of the terminal can be carried out,and finally the data collected by the terminal can be sent to the base station.Based on the above technology,this paper proposes an optimization scheme of wireless data and power transmission system.The feedback of MIMO full feedback system is too large.In practice,the MIMO uplink multiple access mode with limited feedback is adopted.In this system,precoding can not completely eliminate the multi-user interference.Compared with full feedback,it will increase the bit error rate and reduce the user available rate.In this case,we design a method to jointly optimize the transmission power and transmission duration to maximize the energy efficiency,The optimization problem considers the different throughput requirements of the terminal and the MIMO channel.The complex fractional optimization problem is transformed into an equivalent integral expression and solved by Lagrangian dual method.Compared with the algorithm that assumes complete feedback in practice,the algorithm in this paper can achieve greater energy efficiency.