Cellular vehicle-to-everything(C-V2X) communications is regarded as a promising and feasible solution for 5G-enabled vehicular communications and networking. In this paper, we investigate the pilot design and channel ...Cellular vehicle-to-everything(C-V2X) communications is regarded as a promising and feasible solution for 5G-enabled vehicular communications and networking. In this paper, we investigate the pilot design and channel estimation problem in MIMO-OFDM-based C-V2X systems with severe co-channel interference due to spectrum reusing among different V2X communication links. By using zero-correlation zone(ZCZ) sequences, we provide an interference-free pilot design scheme and a corresponding time-domain(TD) correlation-based channel estimation(TD-CCE) method. We employ the ZCZ sequences from the same family set to be designed as the TD pilot symbols and guarantee the pilot sequeneces for neighboring V2X communication links are code-division multiplexing(CDM). The co-channel pilot interference of the deisgned pilot symbols can be effectively eliminated by exploiting the provided TD-CCE method. Simulation results indicate that the accuracy of channel estimation can be effectively improved by the proposed scheme, whose performance is close to that of the non-interference situation.展开更多
With the ever-growing number of base stations(BSs)and user equipments(UEs)in ultra-dense networks(UDN),reusing the same pilot sequences among the cells is inevitable.With pilot reuse scheme,the channel estimation obta...With the ever-growing number of base stations(BSs)and user equipments(UEs)in ultra-dense networks(UDN),reusing the same pilot sequences among the cells is inevitable.With pilot reuse scheme,the channel estimation obtained at a BS contains not only the desired channel-state information(CSI)but also interference from neighboring cells,which can severely degrade CSI estimation performance and adversely affect communication performance.In this paper we consider a pilot contamination avoidance based on pilot pattern design for UDN where the pilot reuse employed and the interfering users from neighboring cells may be not at lower power levels at the BS compared to the in-cell users.We present a novel statistical interference model of sub-carriers to describe the non-deterministic interference from neighboring cells.Then,we provide a pilot pattern design model with non-uniform pilot distribution.Based on this,a pilot contamination avoidance based on pilot pattern design is proposed where pilot reuse scheme and the non-deterministic interference from neighboring cells are taken into consideration.Unlike existing interference mitigation approaches,the proposed method eliminates interference through the method of interference avoidance and can be applied to different kinds of channel estimation algorithms.Simulation results showed that the proposed approach can effectively avoid the interference and ensure the accuracy of channel estimation.展开更多
随着移动通信技术不断创新与发展,对通信的可靠性和数据传输性能提出了更高要求。准确高效地获取信道状态信息(Channel State Information,CSI)是充分发挥无线通信系统各项技术潜能的关键前提。针对多输入多输出-正交频分复用(MIMO-OFDM...随着移动通信技术不断创新与发展,对通信的可靠性和数据传输性能提出了更高要求。准确高效地获取信道状态信息(Channel State Information,CSI)是充分发挥无线通信系统各项技术潜能的关键前提。针对多输入多输出-正交频分复用(MIMO-OFDM)系统中导频开销大及信道估计准确性低的问题,设计了一种基于深度学习的导频设计和信道估计联合优化方案(AE-DRSN)。该方案首先利用Concrete自编码器来识别和选择具有最大信息量的导频位置,从而实现导频优化。然后,将优化后的导频位置输入深度残差收缩网络获取更精确的CSI,进一步完成信道的精确估计。实验结果表明,与传统的信道估计方法相比,基于AE-DRSN的联合优化方案在少量的导频开销下仍能实现高精度的信道估计,充分验证了该方案的有效性。展开更多
文摘Cellular vehicle-to-everything(C-V2X) communications is regarded as a promising and feasible solution for 5G-enabled vehicular communications and networking. In this paper, we investigate the pilot design and channel estimation problem in MIMO-OFDM-based C-V2X systems with severe co-channel interference due to spectrum reusing among different V2X communication links. By using zero-correlation zone(ZCZ) sequences, we provide an interference-free pilot design scheme and a corresponding time-domain(TD) correlation-based channel estimation(TD-CCE) method. We employ the ZCZ sequences from the same family set to be designed as the TD pilot symbols and guarantee the pilot sequeneces for neighboring V2X communication links are code-division multiplexing(CDM). The co-channel pilot interference of the deisgned pilot symbols can be effectively eliminated by exploiting the provided TD-CCE method. Simulation results indicate that the accuracy of channel estimation can be effectively improved by the proposed scheme, whose performance is close to that of the non-interference situation.
基金This work was supported in part by the Chongqing Research Program of Basic Research and Frontier Technology under Grant cstc2019jcyj-msxmX0233in part by Science and Technology Research Program of Chongqing Education Commission of China under Grant KJQN201901125,Grant KJQN201901103in part by the Scientific Research Foundation of Chongqing University of Technology under Grant 2019ZD42,Grant 2019ZD63.
文摘With the ever-growing number of base stations(BSs)and user equipments(UEs)in ultra-dense networks(UDN),reusing the same pilot sequences among the cells is inevitable.With pilot reuse scheme,the channel estimation obtained at a BS contains not only the desired channel-state information(CSI)but also interference from neighboring cells,which can severely degrade CSI estimation performance and adversely affect communication performance.In this paper we consider a pilot contamination avoidance based on pilot pattern design for UDN where the pilot reuse employed and the interfering users from neighboring cells may be not at lower power levels at the BS compared to the in-cell users.We present a novel statistical interference model of sub-carriers to describe the non-deterministic interference from neighboring cells.Then,we provide a pilot pattern design model with non-uniform pilot distribution.Based on this,a pilot contamination avoidance based on pilot pattern design is proposed where pilot reuse scheme and the non-deterministic interference from neighboring cells are taken into consideration.Unlike existing interference mitigation approaches,the proposed method eliminates interference through the method of interference avoidance and can be applied to different kinds of channel estimation algorithms.Simulation results showed that the proposed approach can effectively avoid the interference and ensure the accuracy of channel estimation.
文摘随着移动通信技术不断创新与发展,对通信的可靠性和数据传输性能提出了更高要求。准确高效地获取信道状态信息(Channel State Information,CSI)是充分发挥无线通信系统各项技术潜能的关键前提。针对多输入多输出-正交频分复用(MIMO-OFDM)系统中导频开销大及信道估计准确性低的问题,设计了一种基于深度学习的导频设计和信道估计联合优化方案(AE-DRSN)。该方案首先利用Concrete自编码器来识别和选择具有最大信息量的导频位置,从而实现导频优化。然后,将优化后的导频位置输入深度残差收缩网络获取更精确的CSI,进一步完成信道的精确估计。实验结果表明,与传统的信道估计方法相比,基于AE-DRSN的联合优化方案在少量的导频开销下仍能实现高精度的信道估计,充分验证了该方案的有效性。
