无线协作通信系统中分集编码与检测技术研究
发布时间：2019-05-08 08:32
【摘要】：新一代移动通信网络系统对通信速率、通信可靠性提出了更高要求，无线协作通信技术由于具备多天线系统的特性，能够有效利用多径传播来满足这些性能要求，故而受到广泛关注。无线协作通信技术的基本思想是通过多个单天线用户终端，构成虚拟天线阵列以协助信源与信宿的通信。该技术通过构建多用户协作的分集编码，有助于提高信道容量、获取分集增益、共享链路资源。基于此，本研究围绕无线协作通信系统中的分集编码技术，从正交转发协议、非正交转发协议、两路中继信道转发协议等方面探究了无线协作分集编码技术的实质问题；同时，针对这些问题提出了一些新的分集编码设计方法和信号检测方法、并进行了相关性能分析。具体而言，本研究的主要结论如下： 1.针对现有分布式空时编码和分布式空频编码应用于高速车载宽带通信系统存在的不足，利用高速车载终端与车外基站通信时信道的多径时变特性，提出可适用于此通信场景的无线协作通信系统模型及相应通信节点间的信道模型。在此基础上，提出一种分布式空时频编码设计方法，其可在通信速率无损耗的前提下，获得此通信场景中潜在的协作分集、时间分集和频率分集增益。同时，针对低信噪比时提出的分布式空时频编码较分布式空频编码误码性能较差的问题，提出了这两种编码方法结合使用的切换策略。 2.针对快衰落、多载波、频率选择性衰落中信道估计困难、开销较大的问题，提出一种差分酉调制多中继协作空频编码。理论分析和仿真结果验证了提出的方法可获得完全的协作和频率分集增益。为进一步优化提出编码方法的误码性能，以接收信号合并信噪比最大为准则，推导了接收信号分集合并的均值信噪比解析式，并由此分析了中继个数、中继位置、合并系数等参数对信噪比取值的影响。由于中继个数、中继位置的优化解在区间的边界点上，为使优化工作有实际意义，确定了常用的中继个数、中继位置，并在此基础上得到了功率分配因子及最大比合并因子比值的理论优化解。仿真实验结果验证了理论优化解的有效性和多参数优化的优越性。 3.针对解码转发方式下差分网络编码对应的中继差分检测复杂度高、差分网络编码环节繁杂的问题，提出一种复数域符号相乘的差分网络编码，立足提出的差分网络编码思想，通过构建的检测方法一，中继可检测得到两路终端的差分分组编码，通过构建的检测方法二，中继可检测得到差分网络编码，无需检测两路发送信息分组，中继的检测复杂度显著降低、处理环节明显减少。同时，为了获取高阶分集增益，基于提出的复数域符号相乘的差分网络编码思想，提出了多中继协作的随机差分空时网络编码，可获得的协作分集阶数为激活中继个数。 4.在多子载波、频率选择性衰落、两路中继转发信道中，提出一种多中继协作的基于AF-CDC-OFDM的差分网络编码方法。通过多个协作中继的分布式循环延时编码和功率放大处理，两路终端发送的差分编码分组可获得完全的协作分集和频率分集增益。两路终端在检测对方的发送信号之前需要消除自身干扰信号，为此，提出了一种基于相关统计的自干扰估计和消除方法。仿真实验结果验证了提出的分集编码方法和自干扰消除方法的有效性。 5.在非正交转发协议中应用机会策略可获得高阶分集增益。为了研究瑞利衰落信道中非正交选择放大转发协议和非正交选择译码转发协议的遍历容量，推导了两种转发协议下遍历容量界的闭式表达式，，通过仿真得到了两种协议在不同备选中继个数时的遍历容量。仿真结果表明：两种协议的遍历容量随备选中继个数的增加而改善；相对而言，低信噪比时非正交选择放大转发协议的遍历容量较大，高信噪比时非正交选择译码转发协议的遍历容量较大。 6.针对非正交转发协议中信号联合似然检测时间复杂度高、检测性能差的问题，提出了一种新的干扰消除快速检测方法，该方法通过最大比合并使强信号帧获得二阶分集增益并先行检测，然后，以检测值消除对弱信号帧的干扰后再检测弱信号帧。理论分析表明，提出的方法可以有效降低检测时间复杂度。此外，通过仿真验证了新检测方法的误比特性能有明显改善，仿真结果表明新方法误比特性能的仿真与理论值在高信噪比时趋于一致。
[Abstract]:The new generation mobile communication network system has higher requirements for communication rate and communication reliability, and the wireless cooperative communication technology can effectively utilize the multi-path propagation to meet the performance requirements due to the characteristics of the multi-antenna system, thus being widely concerned. The basic idea of the wireless cooperative communication technology is to form a virtual antenna array through a plurality of single-antenna user terminals to assist the communication between the source and the sink. The technology can improve the channel capacity, acquire the diversity gain and share the link resources by building the diversity coding of the multi-user cooperation. Based on this, the present study probes into the merits of the wireless cooperative diversity coding technology from the aspects of the orthogonal forward protocol, the non-orthogonal forward protocol, the two-way relay channel forwarding protocol, and the like in the wireless cooperative communication system, and meanwhile, In this paper, some new methods of diversity coding design and signal detection are put forward, and the relevant performance analysis is carried out. Specifically, the main conclusions of this study are as follows: 1. Aiming at the defects that the existing distributed space-time coding and the distributed space-frequency coding are applied to the high-speed on-board broadband communication system, the multipath time-variant of the channel when the high-speed vehicle-mounted terminal is in communication with the outside base station the invention provides a wireless cooperative communication system model applicable to the communication scene and a channel mode among the corresponding communication nodes, On the basis of this, a distributed null time-frequency coding design method is proposed, which can obtain the potential cooperative diversity, time diversity and frequency diversity in the communication scene on the premise of no loss of communication rate. In the meantime, at the same time, in the case of the low signal-to-noise ratio, the distributed null time-frequency coding is less than that of the distributed null-frequency code, and the switching scheme used in combination with the two coding methods is put forward. In ord to solve that problem of difficulty in channel estimation and high overhead in fast fading, multi-carrier and frequency selective fading, a kind of differential coherent modulation multi-relay cooperation is proposed. The theoretical analysis and the simulation results verify that the proposed method can obtain full cooperation and frequency division In order to further optimize the error-error performance of the proposed coding method, the signal-to-noise ratio (SNR) of the received signal is derived, and the signal-to-noise ratio (SNR) of the received signal is analyzed, and the value of the signal-to-noise ratio (SNR) of the relay number, the relay location, the merging coefficient and the like is analyzed. The influence of the relay number and the relay position is the boundary point of the interval. In order to make the optimization work practical, the common relay number and the relay position are determined, and the theory of the ratio of the power distribution factor and the maximum ratio combining factor is obtained. The results of the simulation show the effectiveness of the theoretical optimization solution and the multi-parameter optimization. 3. The differential network coding corresponding to the differential network coding in the decoding and forwarding mode is high, the complexity of the differential network coding links is complicated, a differential network coding with a plurality of domain symbols is proposed, the proposed differential network coding method is based on the proposed differential network coding method, the detection method 1, the relay can detect the differential packet code of the two terminals, the detection method 2 and the relay can be detected to obtain the differential network coding, the detection complexity of the relay is obviously reduced, and the processing ring in addition, in ord to obtain high-order diversity gain, a multi-relay cooperative random differential space-time network coding is put forward in order to obtain high-order diversity gain, number of live trunks.4. In multi-carrier, frequency selective fading, two-way relay forwarding channels, a multi-relay cooperative AF-CDC-OFDM based difference is proposed by means of distributed cyclic delay coding and power amplification processing of a plurality of cooperative relays, the differential coding packets sent by the two terminals can obtain full cooperation diversity, and the two-way terminal needs to eliminate the self-interference signal before the transmission signal of the other side is detected, The results of the simulation show the proposed diversity coding method and the self-interference cancellation method. the effectiveness of the method.5. Apply the opportunity policy in a non-orthogonal forwarding protocol In ord to study that traversal capacity of the non-orthogonal selective amplify and forward protocol and the non-orthogonal selective decode and forward protocol in the Rayleigh fading channel, the closed expression of the traverse capacity boundary under two forward protocols is derived. The simulation results show that the ergodic capacity of the two protocols is improved with the increase of the number of alternative relay. In order to solve the problem of high complexity and poor detection performance of signal joint-likelihood detection in non-orthogonal forward protocol, a new method for fast detection of interference cancellation is proposed. the set gain is first detected and then the weak signal frame is eliminated with a detection value and the weak signal frame is detected after the interference of the interference, the theoretical analysis shows that the proposed method can in addition, that error bit performance of the new detection method is obviously improve by simulation, and the simulation result shows that the simulation and the theory of the error bit performance of the new method
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.5
本文编号：2471757
[Abstract]:The new generation mobile communication network system has higher requirements for communication rate and communication reliability, and the wireless cooperative communication technology can effectively utilize the multi-path propagation to meet the performance requirements due to the characteristics of the multi-antenna system, thus being widely concerned. The basic idea of the wireless cooperative communication technology is to form a virtual antenna array through a plurality of single-antenna user terminals to assist the communication between the source and the sink. The technology can improve the channel capacity, acquire the diversity gain and share the link resources by building the diversity coding of the multi-user cooperation. Based on this, the present study probes into the merits of the wireless cooperative diversity coding technology from the aspects of the orthogonal forward protocol, the non-orthogonal forward protocol, the two-way relay channel forwarding protocol, and the like in the wireless cooperative communication system, and meanwhile, In this paper, some new methods of diversity coding design and signal detection are put forward, and the relevant performance analysis is carried out. Specifically, the main conclusions of this study are as follows: 1. Aiming at the defects that the existing distributed space-time coding and the distributed space-frequency coding are applied to the high-speed on-board broadband communication system, the multipath time-variant of the channel when the high-speed vehicle-mounted terminal is in communication with the outside base station the invention provides a wireless cooperative communication system model applicable to the communication scene and a channel mode among the corresponding communication nodes, On the basis of this, a distributed null time-frequency coding design method is proposed, which can obtain the potential cooperative diversity, time diversity and frequency diversity in the communication scene on the premise of no loss of communication rate. In the meantime, at the same time, in the case of the low signal-to-noise ratio, the distributed null time-frequency coding is less than that of the distributed null-frequency code, and the switching scheme used in combination with the two coding methods is put forward. In ord to solve that problem of difficulty in channel estimation and high overhead in fast fading, multi-carrier and frequency selective fading, a kind of differential coherent modulation multi-relay cooperation is proposed. The theoretical analysis and the simulation results verify that the proposed method can obtain full cooperation and frequency division In order to further optimize the error-error performance of the proposed coding method, the signal-to-noise ratio (SNR) of the received signal is derived, and the signal-to-noise ratio (SNR) of the received signal is analyzed, and the value of the signal-to-noise ratio (SNR) of the relay number, the relay location, the merging coefficient and the like is analyzed. The influence of the relay number and the relay position is the boundary point of the interval. In order to make the optimization work practical, the common relay number and the relay position are determined, and the theory of the ratio of the power distribution factor and the maximum ratio combining factor is obtained. The results of the simulation show the effectiveness of the theoretical optimization solution and the multi-parameter optimization. 3. The differential network coding corresponding to the differential network coding in the decoding and forwarding mode is high, the complexity of the differential network coding links is complicated, a differential network coding with a plurality of domain symbols is proposed, the proposed differential network coding method is based on the proposed differential network coding method, the detection method 1, the relay can detect the differential packet code of the two terminals, the detection method 2 and the relay can be detected to obtain the differential network coding, the detection complexity of the relay is obviously reduced, and the processing ring in addition, in ord to obtain high-order diversity gain, a multi-relay cooperative random differential space-time network coding is put forward in order to obtain high-order diversity gain, number of live trunks.4. In multi-carrier, frequency selective fading, two-way relay forwarding channels, a multi-relay cooperative AF-CDC-OFDM based difference is proposed by means of distributed cyclic delay coding and power amplification processing of a plurality of cooperative relays, the differential coding packets sent by the two terminals can obtain full cooperation diversity, and the two-way terminal needs to eliminate the self-interference signal before the transmission signal of the other side is detected, The results of the simulation show the proposed diversity coding method and the self-interference cancellation method. the effectiveness of the method.5. Apply the opportunity policy in a non-orthogonal forwarding protocol In ord to study that traversal capacity of the non-orthogonal selective amplify and forward protocol and the non-orthogonal selective decode and forward protocol in the Rayleigh fading channel, the closed expression of the traverse capacity boundary under two forward protocols is derived. The simulation results show that the ergodic capacity of the two protocols is improved with the increase of the number of alternative relay. In order to solve the problem of high complexity and poor detection performance of signal joint-likelihood detection in non-orthogonal forward protocol, a new method for fast detection of interference cancellation is proposed. the set gain is first detected and then the weak signal frame is eliminated with a detection value and the weak signal frame is detected after the interference of the interference, the theoretical analysis shows that the proposed method can in addition, that error bit performance of the new detection method is obviously improve by simulation, and the simulation result shows that the simulation and the theory of the error bit performance of the new method
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.5
【参考文献】
相关期刊论文 前3条
1 赵贤敬;郑宝玉;;一种协同分集方案的误码性能分析[J];电子学报;2007年07期
2 罗涛;李祥明;王健康;乐光新;;基于空时分组编码的协同通信系统性能的研究[J];电子与信息学报;2007年09期
3 张勇;徐友云;蔡跃明;;非正交选择译码转发协同[J];电子与信息学报;2008年09期
本文编号：2471757
本文链接：https://www.wllwen.com/kejilunwen/wltx/2471757.html
