| This paper studies OFDM channel estimation techniques and their applications inportable communication systems.It is used for fire control or emergency operations andthe design.The target is that the mobile node can transmite SD video and voice incomplex environment, so that the center node could conductor and observe the siteconditions in real-time. As the key technology, Channel Estimation(CE) technologycan overcome the time-varying fading characteristics of wireless channel and resistinter-symbol interference, getting low BER of the signal transmission,so CE study hasvery important meaning and value. Works are as follows：1) This paper analyzes the wireless channel transmission characteristics and itsimpact, studying two channel mode: EPA and lTU-6on foundation of channelmodeling,then builds software simulation platform of channels.2) This paper gives brief exposition of pilot selection, insertion, and pilot patternbased on transmission model of the channel estimated, then studies CE algorithmsbased on the pilot symbol assisted OFDM system and do algorithm theory analysis andsimulation comparison at the same time, providing the basis for the CE design inwireless portable communication system.3) Combined with application environment of system it selects LS aogorithmplus first-order linear interpolation as a CE algorithm focusing on the equipmentportability.The simulation results shows that this design performance improves a lotcompared with LTE plan and it simplifies the design, at the same time it gets circuitstructure plan through comparison of the floating-point and fixed-point simulation.4) According to the design and plan,it used VerilogHDL to complete the circuitstructure design, and did functional simulation verification and circuit test validation,results showed that the circuit design was correct.Circuit performance was the samewith fix point simulation in MATLAB, meeting the design objectives. |
