In this paper, we focus on the pilot-assisted transmission design for downlink URLLC over nonreciprocal channels, in which the multi-antenna controller sends mission-critical data signals to a singleantenna actuator. ...In this paper, we focus on the pilot-assisted transmission design for downlink URLLC over nonreciprocal channels, in which the multi-antenna controller sends mission-critical data signals to a singleantenna actuator. In this system, the prior knowledge of downlink channel state information(CSI) is a prerequisite for reliable data transmission. Generally, the acquisition of downlink CSI is completed either via the uplink pilot measurement exploiting channel reciprocity and time-division duplex(TDD) operation, or via the downlink pilot measurement with quantized feedback and frequency division duplex(FDD) operation. Inspired by this, we aim to investigate how the degree of channel non-reciprocity impacts the transmission reliability of our URLLC system, and the superiority between the TDD mode and FDD mode in terms of transmission reliability maximization. To describe the degree of reliability loss, we derive the closed-form approximations on the transmission error probability of URLLC in TDD and FDD modes, via leveraging the Gauss-Hermite and Gauss-Chebyshev quadrature rules. Following by the theoretical approximations, we demonstrate how to determine the optimal training pilot length and quantized feedback duration that maximize the transmission reliability under given latency constraint. Through numerical results,we validate the accuracy of theoretical approximations derived in this paper, and obtain some meaningful conclusions.展开更多
基金supported in part by the National Natural Science Foundation of China (NSFC) under Grant No. 62071373in part by the Innovation Talents Promotion Program of Shaanxi Province under Grant No. 2021TD-08+1 种基金in part by Fundamental Research Funds for the Central Universities under Grant No. xzy022020055in part by the Zhejiang Lab’s International Talent Fund for Young Professionals。
文摘In this paper, we focus on the pilot-assisted transmission design for downlink URLLC over nonreciprocal channels, in which the multi-antenna controller sends mission-critical data signals to a singleantenna actuator. In this system, the prior knowledge of downlink channel state information(CSI) is a prerequisite for reliable data transmission. Generally, the acquisition of downlink CSI is completed either via the uplink pilot measurement exploiting channel reciprocity and time-division duplex(TDD) operation, or via the downlink pilot measurement with quantized feedback and frequency division duplex(FDD) operation. Inspired by this, we aim to investigate how the degree of channel non-reciprocity impacts the transmission reliability of our URLLC system, and the superiority between the TDD mode and FDD mode in terms of transmission reliability maximization. To describe the degree of reliability loss, we derive the closed-form approximations on the transmission error probability of URLLC in TDD and FDD modes, via leveraging the Gauss-Hermite and Gauss-Chebyshev quadrature rules. Following by the theoretical approximations, we demonstrate how to determine the optimal training pilot length and quantized feedback duration that maximize the transmission reliability under given latency constraint. Through numerical results,we validate the accuracy of theoretical approximations derived in this paper, and obtain some meaningful conclusions.
