基于TR的超宽带智能反射面建模与优化

Modeling and optimization of ultra-wideband intelligent reflecting surface based on time reversal

针对超宽带智能反射面(IRS)无线通信系统中的时延扩展会造成符号间干扰(ISI)及影响系统性能的问题,研究了基于时间反演(TR)的超宽带IRS无线通信系统建模与优化.首先,基于Rake接收机建立了干扰分析模型,分析了Rake接收机的抽头参数对信干噪比(SINR)、误比特率(BER)的影响.仿真分析表明:与1 GHz带宽相比,2GHz带宽下的ISI使得IRS无线通信系统SINR降低4.73 dB,BER性能损失789%.其次,将TR技术引入到超宽带IRS无线通信系统,在接入点(AP)使用TR技术进行预滤波,利用TR技术的时空聚焦特性抑制IRS通信系统ISI,并提出了一种基于TR技术的联合优化AP端TR预滤波器波形和IRS反射因子新算法.仿真结果表明:与随机相位算法相比,新算法将IRS无线通信系统和速率提升了165%.

The inter-symbol interference(ISI) problem and system performance are significantly affected by the delay spread in ultra-wideband intelligent reflecting surface(IRS) wireless communication systems. Modeling and optimization of ultra-wideband IRS wireless communication systems based on time reversal(TR) were studied to overcome this problem. First, the interference analysis model was established based on the Rake receiver and the influence of tap parameter of the Rake receiver on signal-tointerference-plus-noise-ratio(SINR) and bit error ratio(BER) was analyzed.Simulation results show that compared with the SINR and BER at 1 GHz bandwidth,ISI at 2 GHz bandwidth reduces the SINR by 4.73 dB and BER by 789%.Then,the TR technology was introduced into the ultra-wideband IRS wireless communication systems,TR technology was leveraged to prefilter at the access point(AP) and spatial-temporal focusing properties of TR technology was used to suppress the ISI of IRS wireless communication systems. A new algorithm based on TR technology was proposed to jointly optimize the waveform of the pre-filter at AP and the reflecting factor of IRS.Simulation results show that the new algorithm improves the sum rate of the IRS wireless communication systems by 165% compared with the sum rate of IRS wireless communication systems adopting the random phase algorithm.