This paper proposes a high-throughput short reference differential chaos shift keying cooperative communication system with the aid of code index modulation,referred to as CIM-SR-DCSK-CC system.In the proposed CIM-SR-...This paper proposes a high-throughput short reference differential chaos shift keying cooperative communication system with the aid of code index modulation,referred to as CIM-SR-DCSK-CC system.In the proposed CIM-SR-DCSK-CC system,the source transmits information bits to both the relay and destination in the first time slot,while the relay not only forwards the source information bits but also sends new information bits to the destination in the second time slot.To be specific,the relay employs an N-order Walsh code to carry additional log_(2)N information bits,which are superimposed onto the SRDCSK signal carrying the decoded source information bits.Subsequently,the superimposed signal carrying both the source and relay information bits is transmitted to the destination.Moreover,the theoretical bit error rate(BER)expressions of the proposed CIMSR-DCSK-CC system are derived over additive white Gaussian noise(AWGN)and multipath Rayleigh fading channels.Compared with the conventional DCSKCC system and SR-DCSK-CC system,the proposed CIM-SR-DCSK-CC system can significantly improve the throughput without deteriorating any BER performance.As a consequence,the proposed system is very promising for the applications of the 6G-enabled lowpower and high-rate communication.展开更多
In this paper,we apply adaptive coded modulation (ACM) schemes to a wireless networked control system (WNCS) to improve the energy efficiency and increase the data rate over a fading channel.To capture the characteris...In this paper,we apply adaptive coded modulation (ACM) schemes to a wireless networked control system (WNCS) to improve the energy efficiency and increase the data rate over a fading channel.To capture the characteristics of varying rate, interference,and routing in wireless transmission channels,the concepts of equivalent delay (ED) and networked condition index (NCI) are introduced.Also,the analytic lower and upper bounds of EDs are obtained.Furthermore,we model the WNCS as a multicontroller switched system (MSS) under consideration of EDs and loss index in the wireless transmission.Sufficient stability condition of the closed-loop WNCS and corresponding dynamic state feedback controllers are derived in terms of linear matrix inequality (LMI). Numerical results show the validity and advantage of our proposed control strategies.展开更多
In this paper,Index Modulation(IM)aided Generalized Space-Time Block Coding(GSTBC)is proposed,which intrinsically exploits the benefits of IM concept,diversity gain and spatial multiplexing gain.Specifically,the infor...In this paper,Index Modulation(IM)aided Generalized Space-Time Block Coding(GSTBC)is proposed,which intrinsically exploits the benefits of IM concept,diversity gain and spatial multiplexing gain.Specifically,the information bits are partitioned into U groups,with each being modulated by IM symbols(i.e.Spatial Modulation(SM),Quadrature SM(QSM),etc).Next,the structure of GSTBC is invoked for each K IM symbol,and a total ofμ=U/K GSTBC codes are transmitted via T time slots.A Block Expectation Propagation(B-EP)detector is designed for the proposed IM-GSTBC structure.Moreover,the theoretical Average Bit Error Probability(ABEP)is derived for our IM-GSTBC system,which is confirmed by the simulation results and helpful for performance evaluation.Simulation results show that our proposed IM-GSTBC system is capable of striking an efficient trade-off between spatial multiplexing gain,spatial diversity gain as well as implementation cost imposed for both small-scale and large-scale MIMO antenna configurations.展开更多
This paper studies wireless vehicular communication(VehCom)in intelligent transportation systems using an orthogonal frequency division multiplexing with index modulation(OFDM-IM).In the concept of IM,data is transmit...This paper studies wireless vehicular communication(VehCom)in intelligent transportation systems using an orthogonal frequency division multiplexing with index modulation(OFDM-IM).In the concept of IM,data is transmitted not only through the modulated symbols but also via the indices of the active subcarriers.In contrast to the original OFDM,OFDM-IM activates only non-zero subcarriers,increasing energy efficiency.However,the pilotassisted channel estimation(CE)method is a significant challenge in OFDM-IM,where the desired pilot subcarrier interval is related to the OFDM-IM subblock length.This paper proposes a walsh-scattered pilot-assisted CE for OFDM-IM VehCom.The optimum walsh-scattered pilot assignment is proposed to improve the transmission efficiency.Furthermore,a space-time block code with a high transmit diversity gain is employed for OFDM-IM VehCom to enhance VehCom's signal quality.The results show that the proposed method performs higher CE accuracy and better bit-error rate with significant spectral and energy efficiencies than conventional methods.展开更多
Watermarking system based on quantization index modulation （QIM） is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronizati...Watermarking system based on quantization index modulation （QIM） is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronization attacks of QIM digital watermarking,a low density parity check （LDPC） code-aided QIM watermarking algorithm is proposed,and the performance of QIM watermarking system can be improved by incorporating LDPC code with message passing estimation/detection framework.Using the theory of iterative estimation and decoding,the watermark signal is decoded by the proposed algorithm through iterative estimation of amplitude scaling parameters and decoding of watermark.The performance of the proposed algorithm is closer to the dirty paper Shannon limit than that of repetition code aided algorithm when the algorithm is attacked by the additive white Gaussian noise.For constant amplitude scaling attacks,the proposed algorithm can obtain the accurate estimation of amplitude scaling parameters.The simulation result shows that the algorithm can obtain similar performance compared to the algorithm without desynchronization.展开更多
The minimum squared Euclidean distance(MSED) of binary multi-h phase codes is presented. The signal segregation degree(SSD) has been put forward to determine MSED of multi-h phase codes. In order to maximize MSED, SSD...The minimum squared Euclidean distance(MSED) of binary multi-h phase codes is presented. The signal segregation degree(SSD) has been put forward to determine MSED of multi-h phase codes. In order to maximize MSED, SSD should be as large as possible. The necessary and sufficient conditions of maximizing SSD are derived. Finally, SSD and the exact formulae for MSED of binary 2-h phase codes are also presented.展开更多
传统的码索引调制(code index modulation,CIM)系统仅通过扩频码和星座符号来承载信息,能量效率和频谱效率都较低,而附加相位作为一种独特的调制符号来承载信息,具有低传输功耗的特点。为了充分利用多天线索引来提高频谱效率,提出了基...传统的码索引调制(code index modulation,CIM)系统仅通过扩频码和星座符号来承载信息,能量效率和频谱效率都较低,而附加相位作为一种独特的调制符号来承载信息,具有低传输功耗的特点。为了充分利用多天线索引来提高频谱效率,提出了基于低功耗设计的高速率广义空间码索引调制(high-rate generalized space code index modulation,HR-GS-CIM)系统。HR-GS-CIM系统通过使用附加相位替代传统的调制符号,并且通过遗传算法(genetic algorithm,GA)来优化设计附加相位,展现了极高的能效优势和性能优势。同时,HR-GS-CIM系统通过引入广义和空间索引的方法,将附加相位、扩频码以及天线索引进行联合映射选择,并采用低复杂度的联合映射选择算法,极大地提高了系统频谱效率。此外,分析了HR-GS-CIM系统的理论性能,并且仿真验证了HR-GS-CIM系统的理论和仿真性能一致。最后,与传统的CIM系统等对比,验证了所提HR-GS-CIM系统具有显著的性能增益。展开更多
在不增加设备体积重量以及提高发射功率的前提下,为满足高码率遥测数据传输的需求,现有的脉冲编码调制-频调(Pulse Code Modulation Frequency Modulation, PCM-FM)遥测系统广泛使用多符号检测(Multiple Symbol Detection, MSD)算法和Tu...在不增加设备体积重量以及提高发射功率的前提下,为满足高码率遥测数据传输的需求,现有的脉冲编码调制-频调(Pulse Code Modulation Frequency Modulation, PCM-FM)遥测系统广泛使用多符号检测(Multiple Symbol Detection, MSD)算法和Turbo乘积码(TPC)技术。调制指数是PCM-FM遥测系统中的重要参数之一,对系统带宽和误码率有重要影响。本文分析了MSD多符号检测算法原理,通过计算互相关系数及Matlab仿真,分析了调制指数大小对带宽和误码率的影响,指出将调制指数设置为0.715较为合适;分析了调制指数偏差对信噪比损耗的影响,利用MSD算法的相位网格图分析了调制指数偏差对误码和码同步的影响,指出随机数据比连“0”或连“1”数据具有更好的容忍能力。展开更多
针对正交码移键控(code shift keying,CSK)误比特率(bit error rate,BER)性能下降和非正交码索引调制(non-orthogonal-code index modulation,N-CIM)未能充分利用扩频码自相关性的不足,提出一种非正交CSK和码索引调制(non-orthogonal-CS...针对正交码移键控(code shift keying,CSK)误比特率(bit error rate,BER)性能下降和非正交码索引调制(non-orthogonal-code index modulation,N-CIM)未能充分利用扩频码自相关性的不足,提出一种非正交CSK和码索引调制(non-orthogonal-CSK-code index modulation,N-CSK-CIM)算法。发送端信息比特分为调制比特和扩频码映射比特;调制比特用来进行符号调制,映射比特映射为扩频码的索引和码相位索引。首先根据调制比特进行符号调制,然后利用映射比特映射的扩频码索引选择同一原始扩频码,并根据码相位索引进行码移键控产生新的扩频码,调制后的符号实部与虚部分别用这一新的扩频码进行扩频。仿真结果表明,在加性高斯白噪声(additive white Gaussian noise,AWGN)信道和瑞利衰落信道中,相同信噪比时,N-CSK-CIM算法的BER性能优于N-CIM算法和正交CSK算法。展开更多
为了进一步提高传统码索引调制(Code Index Modulation, CIM)的误码率性能和降低伪随机(Pseudo Noise, PN)码索引资源的耗费量,提出非正交分组-码索引调制(Nonorthogonal Grouping-Code Index Modulation, NG-CIM)方案。NG-CIM在发送端...为了进一步提高传统码索引调制(Code Index Modulation, CIM)的误码率性能和降低伪随机(Pseudo Noise, PN)码索引资源的耗费量,提出非正交分组-码索引调制(Nonorthogonal Grouping-Code Index Modulation, NG-CIM)方案。NG-CIM在发送端将每一个传输时隙并行分为调制块和映射块,调制块通过比特分组后映射成为多组调制符号,映射块为各组调制符号的正交分量和同相分量索引相同的PN码进行直接序列扩频传输。仿真结果表明,在加性高斯白噪声信道中,随着频谱效率的提升,NG-CIM的误码率性能较CIM有着约2~4dB的改善,同时PN码资源的耗费量也大大减少。展开更多
基金supported in part by the NSF of China under Grant 62322106,62071131 and 62171135the Guangdong Basic and Applied Basic Research Foundation under Grant 2022B1515020086+2 种基金the NSF of Guangdong Province under Grant 2019A1515011465the International Collaborative Research Program of Guangdong Science and Technology Department under Grant 2022A0505050070the Industrial R&D Project of Haoyang Electronic Co.,Ltd.under Grant 2022440002001494.
文摘This paper proposes a high-throughput short reference differential chaos shift keying cooperative communication system with the aid of code index modulation,referred to as CIM-SR-DCSK-CC system.In the proposed CIM-SR-DCSK-CC system,the source transmits information bits to both the relay and destination in the first time slot,while the relay not only forwards the source information bits but also sends new information bits to the destination in the second time slot.To be specific,the relay employs an N-order Walsh code to carry additional log_(2)N information bits,which are superimposed onto the SRDCSK signal carrying the decoded source information bits.Subsequently,the superimposed signal carrying both the source and relay information bits is transmitted to the destination.Moreover,the theoretical bit error rate(BER)expressions of the proposed CIMSR-DCSK-CC system are derived over additive white Gaussian noise(AWGN)and multipath Rayleigh fading channels.Compared with the conventional DCSKCC system and SR-DCSK-CC system,the proposed CIM-SR-DCSK-CC system can significantly improve the throughput without deteriorating any BER performance.As a consequence,the proposed system is very promising for the applications of the 6G-enabled lowpower and high-rate communication.
基金National Outstanding Youth Founda-tion (No.60525303)National Natural Science Foundation of China(No.60404022,60704009)Natural Science Foundation of Hebei Province (No.F2005000390,F2006000270).
文摘In this paper,we apply adaptive coded modulation (ACM) schemes to a wireless networked control system (WNCS) to improve the energy efficiency and increase the data rate over a fading channel.To capture the characteristics of varying rate, interference,and routing in wireless transmission channels,the concepts of equivalent delay (ED) and networked condition index (NCI) are introduced.Also,the analytic lower and upper bounds of EDs are obtained.Furthermore,we model the WNCS as a multicontroller switched system (MSS) under consideration of EDs and loss index in the wireless transmission.Sufficient stability condition of the closed-loop WNCS and corresponding dynamic state feedback controllers are derived in terms of linear matrix inequality (LMI). Numerical results show the validity and advantage of our proposed control strategies.
基金supported in part by the National Key Research and Development Program of China under Grant 2021YFB2900500in part by the National Science Foundation of China under Grant 62001179+1 种基金in part by the Fundamental Research Funds for the Central Universities under Grant 2020kfyXJJS111。
文摘In this paper,Index Modulation(IM)aided Generalized Space-Time Block Coding(GSTBC)is proposed,which intrinsically exploits the benefits of IM concept,diversity gain and spatial multiplexing gain.Specifically,the information bits are partitioned into U groups,with each being modulated by IM symbols(i.e.Spatial Modulation(SM),Quadrature SM(QSM),etc).Next,the structure of GSTBC is invoked for each K IM symbol,and a total ofμ=U/K GSTBC codes are transmitted via T time slots.A Block Expectation Propagation(B-EP)detector is designed for the proposed IM-GSTBC structure.Moreover,the theoretical Average Bit Error Probability(ABEP)is derived for our IM-GSTBC system,which is confirmed by the simulation results and helpful for performance evaluation.Simulation results show that our proposed IM-GSTBC system is capable of striking an efficient trade-off between spatial multiplexing gain,spatial diversity gain as well as implementation cost imposed for both small-scale and large-scale MIMO antenna configurations.
文摘This paper studies wireless vehicular communication(VehCom)in intelligent transportation systems using an orthogonal frequency division multiplexing with index modulation(OFDM-IM).In the concept of IM,data is transmitted not only through the modulated symbols but also via the indices of the active subcarriers.In contrast to the original OFDM,OFDM-IM activates only non-zero subcarriers,increasing energy efficiency.However,the pilotassisted channel estimation(CE)method is a significant challenge in OFDM-IM,where the desired pilot subcarrier interval is related to the OFDM-IM subblock length.This paper proposes a walsh-scattered pilot-assisted CE for OFDM-IM VehCom.The optimum walsh-scattered pilot assignment is proposed to improve the transmission efficiency.Furthermore,a space-time block code with a high transmit diversity gain is employed for OFDM-IM VehCom to enhance VehCom's signal quality.The results show that the proposed method performs higher CE accuracy and better bit-error rate with significant spectral and energy efficiencies than conventional methods.
基金National Natural Science Foundation of China(No.61272432)Qingdao Science and Technology Development Plan(No.12-1-4-6-(10)-jch)
文摘Watermarking system based on quantization index modulation （QIM） is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronization attacks of QIM digital watermarking,a low density parity check （LDPC） code-aided QIM watermarking algorithm is proposed,and the performance of QIM watermarking system can be improved by incorporating LDPC code with message passing estimation/detection framework.Using the theory of iterative estimation and decoding,the watermark signal is decoded by the proposed algorithm through iterative estimation of amplitude scaling parameters and decoding of watermark.The performance of the proposed algorithm is closer to the dirty paper Shannon limit than that of repetition code aided algorithm when the algorithm is attacked by the additive white Gaussian noise.For constant amplitude scaling attacks,the proposed algorithm can obtain the accurate estimation of amplitude scaling parameters.The simulation result shows that the algorithm can obtain similar performance compared to the algorithm without desynchronization.
文摘The minimum squared Euclidean distance(MSED) of binary multi-h phase codes is presented. The signal segregation degree(SSD) has been put forward to determine MSED of multi-h phase codes. In order to maximize MSED, SSD should be as large as possible. The necessary and sufficient conditions of maximizing SSD are derived. Finally, SSD and the exact formulae for MSED of binary 2-h phase codes are also presented.
文摘传统的码索引调制(code index modulation,CIM)系统仅通过扩频码和星座符号来承载信息,能量效率和频谱效率都较低,而附加相位作为一种独特的调制符号来承载信息,具有低传输功耗的特点。为了充分利用多天线索引来提高频谱效率,提出了基于低功耗设计的高速率广义空间码索引调制(high-rate generalized space code index modulation,HR-GS-CIM)系统。HR-GS-CIM系统通过使用附加相位替代传统的调制符号,并且通过遗传算法(genetic algorithm,GA)来优化设计附加相位,展现了极高的能效优势和性能优势。同时,HR-GS-CIM系统通过引入广义和空间索引的方法,将附加相位、扩频码以及天线索引进行联合映射选择,并采用低复杂度的联合映射选择算法,极大地提高了系统频谱效率。此外,分析了HR-GS-CIM系统的理论性能,并且仿真验证了HR-GS-CIM系统的理论和仿真性能一致。最后,与传统的CIM系统等对比,验证了所提HR-GS-CIM系统具有显著的性能增益。
文摘在不增加设备体积重量以及提高发射功率的前提下,为满足高码率遥测数据传输的需求,现有的脉冲编码调制-频调(Pulse Code Modulation Frequency Modulation, PCM-FM)遥测系统广泛使用多符号检测(Multiple Symbol Detection, MSD)算法和Turbo乘积码(TPC)技术。调制指数是PCM-FM遥测系统中的重要参数之一,对系统带宽和误码率有重要影响。本文分析了MSD多符号检测算法原理,通过计算互相关系数及Matlab仿真,分析了调制指数大小对带宽和误码率的影响,指出将调制指数设置为0.715较为合适;分析了调制指数偏差对信噪比损耗的影响,利用MSD算法的相位网格图分析了调制指数偏差对误码和码同步的影响,指出随机数据比连“0”或连“1”数据具有更好的容忍能力。
文摘针对正交码移键控(code shift keying,CSK)误比特率(bit error rate,BER)性能下降和非正交码索引调制(non-orthogonal-code index modulation,N-CIM)未能充分利用扩频码自相关性的不足,提出一种非正交CSK和码索引调制(non-orthogonal-CSK-code index modulation,N-CSK-CIM)算法。发送端信息比特分为调制比特和扩频码映射比特;调制比特用来进行符号调制,映射比特映射为扩频码的索引和码相位索引。首先根据调制比特进行符号调制,然后利用映射比特映射的扩频码索引选择同一原始扩频码,并根据码相位索引进行码移键控产生新的扩频码,调制后的符号实部与虚部分别用这一新的扩频码进行扩频。仿真结果表明,在加性高斯白噪声(additive white Gaussian noise,AWGN)信道和瑞利衰落信道中,相同信噪比时,N-CSK-CIM算法的BER性能优于N-CIM算法和正交CSK算法。
文摘为了进一步提高传统码索引调制(Code Index Modulation, CIM)的误码率性能和降低伪随机(Pseudo Noise, PN)码索引资源的耗费量,提出非正交分组-码索引调制(Nonorthogonal Grouping-Code Index Modulation, NG-CIM)方案。NG-CIM在发送端将每一个传输时隙并行分为调制块和映射块,调制块通过比特分组后映射成为多组调制符号,映射块为各组调制符号的正交分量和同相分量索引相同的PN码进行直接序列扩频传输。仿真结果表明,在加性高斯白噪声信道中,随着频谱效率的提升,NG-CIM的误码率性能较CIM有着约2~4dB的改善,同时PN码资源的耗费量也大大减少。
