Measurement Scheme Design For Micro-power Wireless Channel

The main task of channel measurement is to acquire the channel characteristics by channel sounding.At present,there are many researchers who study channel measurement,but few people study the frequency band of 470-510 MHz for micro-power wireless channel.Since the micro-power wireless channel belongs to the non-dedicated frequency band,the transmission environment of the channel is relatively bad,and it is very different from other frequency bands.In addition,due to different application scenarios,the requirements for channel measurement are different,so the existing channel measurement scheme is no longer applicable.Therefore,this thesis will study and improve some key technologies of channel measurement,so as to design the micro-power wireless channel measurement scheme and obtain channel characteristics for some scenarios by channel sounding.In view of the problem of poor micro-power wireless channel transmission environment and insufficient channel estimation performance,some key technologies of micro-power wireless channel measurement are studied and improved in this thesis.The main contents include measurement sequence selection,channel impulse response(CIR)extraction,and measurement data denoising for low signal to noise ratio(SNR).When studying the probing sequence,the channel estimation performance of different types and different lengths of probing sequences is analyzed.The simulation results show that the Zadoff-chu sequence is more suitable for sounding micro-power wireless channel.In the study of channel impulse response extraction,the serial interference cancellation(SIC)algorithm is improved by the sliding correlation algorithm and the improved SIC algorithm is proposed.The simulation results show that the performance of the improved SIC algorithm is better than that of the sliding correlation algorithm.In addition,the empirical mode decomposition(EMD)algorithm is introduced to measurement data denoising in low SNR.The final simulation results show that when the signal-to-noise ratio of the measurement data is low,the denoising algorithm can eliminate some noise and maintain the correlation performance of the measurement data.Aiming at the measurement requirements of micro-power wireless channel,this thesis designs a measurement scheme for micro-power wireless channel,and obtains the channel characteristics of some scenes by channel sounding.In the measurement scheme,the sounding system is built based on the sliding correlation measurementmethod.Then the frame structure of the sounding signal is designed based on the zero-auto correlation property of the Zadoff-chu sequence.After explaining some parameter configuration and data processing flow of the measurement scheme,the performance of the measurement scheme is analyzed,and the feasibility of the measurement scheme is verified.