Research And Implementation Of High Sensitivity Of TC-OFDM Receiver Technology

Location Based Services has a significant impact on domestic and foreign market and a wide application in all works of life.However,technological development is inseparable from LBS positioning and navigation technology,especially indoor positioning and navigation,lots of technical difficulties need to be overcome.Based on indoor and outdoor navigation system--TC-OFDM system,this article study the method of high sensitivity receiver,communication interfaces and protocol design in-depth.Combined with the public user close highly,the system is constructed based on the mobile base stations to achieve meter level accuracy positioning and wide coverage.My work is shown as follows:(1)Based on TC-OFDM system,my work proposed a differential coherent integration priori optimization algorithm,this algorithm predicts firstly and tests later and improves the receiver's sensitive quality.Simulation results depict that the coherent value of the optimization algorithm at a level of 10^12 rather than 10^6 as the traditional algorithms.In addition,optimization of noise fluctuations are smaller than traditional algorithms,capture higher sensitivity,improved receiver performance.It not only avoids the square loss,but also reduces the influence of a data bit transition.In addition,analysis of the coupled CDMA and OFDM,TC-OFDM signal ranging method which can effectively reduce the urban complex environments ranging error caused by multipath.(2)For TC-OFDM with GPS/Compass integration baseband,baseband interface design proposes an SPI-based,and designed a data communication protocol.Meanwhile,proposed a switching method of TC-OFDM with GPS/Compass baseband clock frequency switching without glitches.These designs and methods to ensure the stability of communication between baseband and ARM and simplifies the amount of data transmission.And it simplifies wiring on chips,less logic resource usage,saving hardware costs.Lastly,implements EBI interface and SPI interface cabling on FPGA.Experimental validation through the SPI interface is simple and convenient,logical unit number is occupied by nearly a quarter EBI interface,saving hardware costs.(3)The TC-OFDM system is verified by experiments.My work also consists of,firstly,analyzing the overall architecture of the hardware and software of the system control flow;secondly,measuring the position precision of the system in Tianjin in the horizontal direction within±2m.