Design Of Ad Hoc Intelligent Router Hardware And Radio Frequency Architecture

With the deepening exploration of the ocean,the research scope expands from from offshore to deep sea.Due to the defects of narrow bandwidth,low communication rate,small capacity,single function and so on,the traditional communication system has been far from meeting the requirements of the fishery communication system.At the same time,as the marine communication environment can not establish communication infrastructure and the ship has mobility,ad hoc network is very suitable for maritime communication scenarios,which requires each communication node to have not only packet forwarding and routing functions,but also complete communication capabilities to meet various maritime communication needs.This thesis studies and designs an ad hoc intelligent router as a network communication node,which is composed of a high-speed communication unit and a lowspeed communication unit.The former is responsible for short-distance large data traffic,while the latter is responsible for long-distance low-speed communication and emergency broadcast.This thesis introduces the characteristics of maritime wireless communication and ad hoc network,analyzes the index requirements of high-speed and low-speed communication system of ad hoc intelligent router,and proposes an ad hoc intelligent router system based on hybrid beamforming MIMO technology,which combines a high-speed communication unit with a short wave low-speed communication unit.The main contents and achievements of this paper are as follows:1.A high-speed communication unit is designed to realize the high-speed multimedia service transmission of ad hoc intelligent router.The communication unit works in the frequency band of 450 MHz,the maximum communication distance is 20 km and the maximum communication rate is over 100 Mbps.Zynq chip is used as the main control of the system,and two ad9361 chips are connected to realize the modulation and demodulation of various signals.The MIMO system of 16T16 R is constructed by using hybrid beam shaping architecture.2.Two hybrid beamforming algorithms,service beamforming and broadcast beamforming,are designed and simulated.The performance of full connection structure and subarray connection structure in hybrid beamforming is compared by simulation,and the suitable MIMO system types of both structures are discussed.3.A DPD method based on array far-field response is designed to solve the linearization problem of power amplifier in massive MIMO system.In this method,the beamforming algorithm is combined with DPD algorithm to reduce the nonlinear distortion of signal in the main beam direction.The hardware connection and algorithm complexity of power amplifier DPD in massivemimo system are simplified,as well as providing a good correction effect.4.A short wave power amplifier module for low speed communication system supporting multi video broadcasting is designed.Each channel can carry 1MHz bandwidth,and has the performance of low spurious,low distortion and low intermodulation.This paper completes the hardware architecture and RF unit design of ad hoc intelligent router.The test results show that the designed system can work normally.