Software Design Of LTE Dual Direction Over Single Cable Indoor Coverage System

With the extensive application of Long Term Evolution(LTE)network,more than 70 percent of teletraffic and 90 percent of data traffic occur in indoor environment.In order to meet the growing communication requirements and improve user experience,it is of great practical significance to build a high-quality indoor coverage environment for enhancing LTE coverage quality.Based on this background,this paper investigates and analyses LTE construction mode,and finally adopts the mode of single cable,dual channel and direction,which shows the advantages of high system capacity,low cost and esay maintenance.In order to realize the design of indoor coverage of single cable,dual channel and bidirectional LTE system,a frequency shift system is designed by using multiple-input multiple-output(MIMO)technology.The MIMO frequency shift system consists of two parts:local equipment and remote equipment.This paper focuses on the design and development of the functional modules of the local and remote devices.A multi-thread control mechanism based on real-time operating system multithreading control is used to realize the collaboration among the threading modules.The management and configuration of the local to the remote is processed by the RF signal transceiver module,which is designed by using frequency-shift keying(FSK)modulation and demodulation mode.The data communication flow is developed and tested,which matches the expectations well.Aiming to realizing the dual channel and bidirectional LTE signal,the bidirectional frequency conversion module is designed by means of frequency division multiplexing.In addition,the mapping structure of parameters and coding is designed and implemented,by which the the information of the network management can be quickly queried and set between local and remote devices.At last,the performances of pulse width modulation(P WM)and pulse density modulation(PDM)are deeply studied.We proposed a novel scheme to generate the PDM signal,which is based on the PWM simulation.In this way,the high-precision digital to analog conversion is realized in the Microcontroller Unit(MCU).The resolution and non-linear error of the proposal are verified and analyzed by simulation and experiment.It shows that our proposal can realize higher resolution and smaller error,which shows a great significance for achieving digital-to-analog(DA)conversion in single-chip computer.