PLL DEMODULATION TECHNIQUE FOR M-RAY POSITION PHASE SHIFT KEYING

The paper presents a kind of transmission system which employs M-ary Position Phase Shift Keying(MPPSK) to send data and Phase Locked Loop(PLL) based techniques for data retrieve.With a single PLL, MPPSK demodulation is achieved, as well as carrier recovery and symbol synchronization.Firstly, MPPSK modulation method is briefly introduced.2PPSK's PSD expression is given with its optimization result.Orthogonal Phase Detector(PD) and static threshold are used for the purpose of wider phase range and simplicity in demodulation.The data rate is alterable, which is 4.65 kbps for 2PPSK and 9.3 kbps for 4PPSK in the paper.Then some indicative comparisons in Signal to Noise Ratio Symbol Error Rate(SNR-SER) are made among 2PPSK, 3PPSK and 4PPSK, of which 4PPSK has proved to be optimal in ten slots each symbol conditions.And finally, it is demonstrated by system simulations that lower than 10-4 Symbol Error Rate(SER) performance can be obtained at 13 dB symbol SNR.

Interactive Kalman Filtering for Differential and Gaussian Frequency Shift Keying Modulation with Application in Bluetooth

Some applications are constrained only to implement low cost receivers. In this case, designers are required to use less complex and non-expensive modulation techniques. Differential Quadrature Phase Shift Keying (DQPSK) and Gaussian Frequency Shift Keying (GFSK) can be non-coherently demodulated with simple algorithms. However, these types of demodulation are not robust and suffer from poor performance. This paper proposes a new method to enhance the performance of DQPSK and GFSK using Interactive Kalman Filtering (IKF) technique, in which a one Unscented Kalman Filter (UKF) and two Kalman Filters (KF) are coupled to optimize the demodulated signals. This method consists of simple but very effective algorithms without adding complexity to the demodulators comparing to other very complex methods. UKF is used in this method due to its superiority in approximating and estimating nonlinear systems and its ability to handle non-Gaussian noise environments. The proposed method has been validated by creating a MATLAB/SIMULINK Bluetooth system model, in which the IKF is integrated into the receiver, which implement both DQPSK and GFSK, and run simulation in Gaussian and Non-Gaussian noise environments. Results have shown the effectiveness of this method in optimizing the received signals, and that the UKF outperforms the Extended Kalman Filter (EKF).

Multiple phase detector of M-ary phase shift keying symbols in code division multiple access systems

A novel iterative technique, the phase descent search detection was proposed. This technique constrained the solution （PDS） algorithm, for M-ary phase shift keying （M-PSK） symbols to have a unit magnitude and it was based on coordinate descent iterations where coordinates were the unknown symbol phases. The PDS algorithm, together with a descent local search （also implemented as a version of the PDS algorithm）, was used multiple times with different initializations in a proposed multiple phase detector; the solution with the minimum cost was then chosen as the final solution. The simulation results show that for highly loaded multiuser scenarios, the proposed technique has a detection performance that is close to the single-user bound. The results also show that the multiple phase detector allows detection in highly overloaded scenarios and it exhibits near-far resistance. In particular, the detector has a performance that is significantly better, and complexity that is significantly lower, than that of the detector based on semi-definite relaxation.

Performance Analysis of AF Relaying Aided Space Shift Keying System with Imperfect Channel Estimation

Space shift keying (SSK) is a spectrally efficient and low-complexity technique that only uses antenna index to convey information.Combining SSK with cooperative communication,the transmission reliability of SSK system can be improved effectively.In this paper,considering imperfect channel information,the performance of cooperative SSK system with amplify-and-forward (AF) relaying protocol is investigated,and the effect of estimation error on the performance is analyzed.According to the performance analysis,the probability density function and moment generating function of effective signal-to-noise ratio are derived,respectively.Using these results,the closed-form expression of average bit error rate (BER) can be achieved.Meanwhile,the asymptotically approximated BER and the corresponding diversity order analysis are presented for the performance evaluation.By computer simulations,the validness of the presented theoretical analysis is verified,and the theoretical BERs with different estimation errors are shown to be close to those of the corresponding simulations.

Adaptive Mapping Generalized Space Shift Keying Modulation

Generalized Space Shift Keying （GSSK） modulation is a low-complexity spatial nmltiplexing technique for nmltiple-antenna wireless systems. However, effective transmit antenna combinations have to be preselected, and there exist redundant antenna combinations which are not used in GSSK. In this paper, a novel adaptive mapping scheme for GSSK modulation, named as Adaptive Mapping Generalized Space Shift Keying （AMGSSK）, is presented. Compared with GSSK, the antenna combinations are updated adaptively according to the Channel State Inforrmtion （CSI） in the proposed AMGSSK system, and the perfonrance of average Symbol Error Rate （SER） is reduced considerably. In the proposed scheme, two algorithrrs for selecting the optimum antenna combinations are described. The SER perfonmnce of AMGSSK is analyzed theoretically, and validated by Monte Carlo sinmlation. It is shown that the proposed AMGSSK scheme has good perfonmnce in SER and spectral efficiency.

Shaped Offset Quadrature Phase Shift Keying Based Waveform for Fifth Generation Communication

Fifth generation(5G)wireless networks must meet the needs of emerging technologies like the Internet of Things(IoT),Vehicle-to-everything(V2X),Video on Demand(VoD)services,Device to Device communication(D2D)and many other bandwidth-hungry multimedia applications that connect a huge number of devices.5G wireless networks demand better bandwidth efficiency,high data rates,low latency,and reduced spectral leakage.To meet these requirements,a suitable 5G waveform must be designed.In this work,a waveform namely Shaped Offset Quadrature Phase Shift Keying based Orthogonal Frequency Division Multiplexing(SOQPSK-OFDM)is proposed for 5G to provide bandwidth efficiency,reduced spectral leakage,and Bit Error Rate(BER).The proposed work is evaluated using a real-time Software Defined Radio(SDR)testbed-Wireless open Access Research Platform(WARP).Experimental and simulation results show that the proposed 5G waveform exhibits better BER performance and reduced Out of Band(OOB)radia-tion when compared with other waveforms like Offset Quadrature Phase Shift Key-ing(OQPSK)and Quadrature Phase Shift Keying(QPSK)based OFDM and a 5G waveform candidate Generalized Frequency Division Multiplexing(GFDM).BER analysis shows that the proposed SOQPSK-OFDM waveform attains a Signal to Noise Ratio(SNR)gain of 7.2 dB at a BER of 10�3,when compared with GFDM in a real-time indoor environment.An SNR gain of 8 and 6 dB is achieved by the proposed work for a BER of 10�4 when compared with QPSK-OFDM and OQPSK-OFDM signals,respectively.A significant reduction in OOB of nearly 15 dB is achieved by the proposed work SOQPSK-OFDM when compared to 16 Quadrature Amplitude Modulation(QAM)mapped OFDM.

Semiconductor optical amplifier used as regenerator for degraded differential phase-shift keying signals

Phase and amplitude regeneration are necessary for degraded differential phase-shift keying communication sys- tems. This paper proposes a regenerator based on semiconductor optical amplifier for differential phase-shift keying signals. The key regeneration mechanism is theoretically analysed. The effectiveness of semiconductor optical amplifier based regenerator is demonstrated by comparing the bit error rate and eye diagrams before and after regeneration for 40-Cbit/s differential phase-shift keying 1080-km transmission systems. The results show that regeneration effects are very well. Bit error rate is tess than 10-12 with the regenerator.

Analysis of the differential-phase-shift-keying protocol in the quantum-key-distribution system

The analysis is based on the error rate and the secure communication rate as functions of distance for three quantum-key-distribution （QKD） protocols： the Bennett-Brassard 1984, the Bennett Brassard Mermin 1992, and the coherent differential-phase-shift keying （DPSK） protocols. We consider the secure communication rate of the DPSK protocol against an arbitrary individual attack, including the most commonly considered intercept-resend and photonnumber splitting attacks, and concluded that the simple and efficient differential-phase-shift-keying protocol allows for more than 200 km of secure communication distance with high communication rates.

时间反转短参考正交双倍速DCSK调制方案

为解决传统差分混沌移位键控(differential chaotic shift keying,DCSK)通信系统传输数据速率低以及安全性差的问题,提出一种时间反转短参考正交双倍速差分混沌移位键控通信系统(time-reversal short reference orthogonal double speed DCSK,TR-SR-ODBR-DCSK)。该方案利用Walsh函数产生两路正交的混沌信号调制两位数据信息,在同一个时隙内同时传输两个比特信息,信息传输速率提高了一倍,同时提高了通信系统的能量利用率;在此基础上将系统中传输的参考信号进行时间反转,消除同一时隙信号间的相关性,提高系统安全性及信号保密性。利用通用软件无线电外设(universal software radio peripheral,USRP)和LabVIEW仿真软件搭建半实物的仿真平台,仿真结果验证了混沌通信系统的可行性和有效性。

基于不变矩和Mean Shift聚类的视频关键帧提取

随着通信和多媒体技术的迅速发展,检索和浏览海量多媒体数据成为日益迫切的问题。关键帧提取技术在基于内容的视频检索中扮演了重要角色。提取的关键帧有两个主要作用:一是用它来静态表示视频的主题;其二是希望从关键帧中提取特征数据,作为多媒体数据库的数据源。以视频场景中运动目标的不变矩为特征提出了一种基于非监督聚类的关键帧提取算法。首先在视频序列中分离出运动目标,然后计算运动目标区域的各阶不变矩,并以不变矩向量作为特征,运用Mean Shift算法聚类有相似特征的视频帧,进而在每类中选取有代表性的视频帧作为关键帧。不同场景下的实验结果证实了本算法的可行性。

基于FPGA的井筒无线电磁短传系统设计

随着油气田勘探开发的持续深化,油气井钻井的质量要求日益提升。针对如何高效、准确地将近钻头处数据跨越螺杆钻具传输至随钻测量系统这一关键问题,提出了一种基于现场可编程门阵列(FPGA)的井筒无线电磁短传系统设计方案。采用XC6SLX16型FPGA芯片,以降低电路设计难度和提高电路设计统一性;基于井筒无线电磁传输原理和二进制频移键控技术,实现信号的调制解调;通过引入快速傅里叶变换(FFT)算法,加快获取信号的频谱信息并完成信号的解调。利用Modelsim仿真工具进行验证,结果表明,FFT算法不仅实现了目标信号和其他信号的快速区分,还显著提升了信号传输的准确性和可靠性。

Adaptive compensating method for Doppler frequency shift using LMS and phase estimation

The novel compensating method directly demodulates the signals without the carrier recovery processes, in which the carrier with original modulation frequency is used as the local coherent carrier. In this way, the phase offsets due to frequency shift are linear. Based on this premise, the compensation processes are： firstly, the phase offsets between the baseband neighbor-symbols after clock recovery is unbiasedly estimated among the reference symbols; then, the receiving signals symbols are adjusted by the phase estimation value; finally, the phase offsets after adjusting are compensated by the least mean squares （LMS） algorithm. In order to express the compensation processes and ability clearly, the quadrature phase shift keying （QPSK） modulation signals are regarded as examples for Matlab simulation. BER simulations are carried out using the Monte-Carlo method. The learning curves are obtained to study the algorithm＇s convergence ability. The constellation figures are also simulated to observe the compensation results directly.

Influence of multi-photon pulses on practical differential-phase-shift quantum key distribution

The influence of multi-photon pulses on practical differcBtial-phase-shift quantum key distribution （DPS-Qt（D） is analysed. We have estimated the information which Eve obtained by PNS （photon-number splitting） attack and BS （beam splitting） attack. The result indicates that the PNS attack and BS attack will not limit the transmission distance as long as we select an appropriate mean photon number. Also, the maximum mean photon number under BS attack in practical DPS-QKD system and the set of practical assumptions about Eve＇s capabilities are presented.

Breaking chaotic shift key communication via adaptive key identification

This paper proposes an adaptive parameter identification method for breaking chaotic shift key communication from the transmitted signal in public channel. The sensitive dependence property of chaos on parameter mismatch is used for chaos adaptive synchronization and parameter identification. An index function about the synchronization error is defined and conjugate gradient method is used to minimize the index function and to search the transmitter＇s parameter （key）. By using proposed method, secure key is recovered from transmitted signal generated by low dimensional chaos and hyper chaos switching communication. Multi-parameters can also be identified from the transmitted signal with noise.

Round-robin differential quadrature phase-shift quantum key distribution

Recently,a round-robin differential phase-shift（RRDPS） protocol was proposed[Nature 509,475（2014）],in which the amount of leakage is bounded without monitoring the signal disturbance.Introducing states of the phase-encoded Bennett-Brassard 1984 protocol（PE-BB84） to the RRDPS,this paper presents another quantum key distribution protocol called round-robin differential quadrature phase-shift（RRDQPS） quantum key distribution.Regarding a train of many pulses as a single packet,the sender modulates the phase of each pulse by one of {0,π/2,π,3π/2},then the receiver measures each packet with a Mach-Zehnder interferometer having a phase basis of 0 or π/2.The RRDQPS protocol can be implemented with essential similar hardware to the PE-BB84,so it has great compatibility with the current quantum system.Here we analyze the security of the RRDQPS protocol against the intercept-resend attack and the beam-splitting attack.Results show that the proposed protocol inherits the advantages arising from the simplicity of the RRDPS protocol and is more robust against these attacks than the original protocol.

Lower bound for the security of differential phase shift quantum key distribution against a one-pulse-attack

Quantum key distribution is the art of sharing secret keys between two distant parties, and has attracted a lot of attention due to its unconditional security. Compared with other quantum key distribution protocols, the differential phase shift quantum key distribution protocol has higher efficiency and simpler apparatus. Unfortunately, the uncondi- tional security of differential phase shift quantum key distribution has not been proved. Utilizing the sharp continuity of the von Neuman entropy and some basic inequalities, we estimate the upper bound for the eavesdropper Eve＇s infor- mation. We then prove the lower bound for the security of the differential phase shift quantum key distribution protocol against a one-pulse attack with Devatak-Winter＇s secret key rate formula.

Passive round-robin differential-quadrature-phase-shift quantum key distribution scheme with untrusted detectors

In this paper, we proposed the scheme for a passive round-robin differential-phase-shift quantum key distribution（RRDPS-QKD） set-up based on the principle of Hong–Ou–Mandel interference. Our scheme requires two legitimate parties to prepare their signal state with two different non-orthogonal bases instead of single in original protocol. Incorporating this characteristic, we establish the level of security of our protocol under the intercept-resend attack and demonstrate its detector-flaw-immune feature. Furthermore, we show that our scheme not only inherits the merit of better tolerance of bit errors and finite-sized-key effects but can be implemented using hardware similar to the measurement device independent QKD（MDI-QKD）. This ensures good compatibility with the current commonly used quantum system.

高速置换索引差分混沌移位键控通信系统

为了提高置换索引差分混沌移位键控系统的数据传输速率和能量效率,提出了高速置换索引差分混沌移位键控通信系统。该系统采用置换矩阵索引多元信息,并携带一个调制位。发射端将参考信号复制P次作为信息承载信号,通过希尔伯特变换,每个信息时隙中多传输N个用户的信息,将信号级联到正交频分复用系统进行正交载波调制,大大提高了系统的数据传输速率;同时推导了该系统在高斯白噪声信道和多径瑞利衰落信道下的误码率表达式。理论分析及仿真结果证明,该系统相比其他置换索引类系统具有高速率、低误码率的良好特性,有更好的应用前景。

串联补偿无线电能传输变换器载波通信研究

无线电能传输(WPT)负载电压、电流等状态信息需送到原边进行闭环控制和监控处理,副边到原边的通信至关重要。首先介绍了电容调制的WPT系统拓扑和工作原理,电容调制与否使得系统拓扑发生变化,未调制时原、副边拓扑为串/串(S/S)结构;调制时原、副边拓扑为串/串并(S/SP)结构。调制电容的投切形成两种状态来传递通信信息,且该状态变化可以反映到原边电流上。其次采用幅移键控(ASK)解调电路对原边电流处理即可还原通信信号,为提高解调精度和抗干扰能力,对ASK解调电路进行改进。最后通过仿真和实验验证了方案的有效性,实验结果表明,该系统在100 W的运行功率、2~5 kHz的通信频率下,可以精准完成副边到原边的通信。

基于SSK的室内VLPC系统设计及性能分析

本文设计了一个多输入单输出(Multiple-Input Single-Output,MISO)的三维室内可见光定位通信一体化(Visible Light Position and Communication,VLPC)系统,该系统在接收端基于接收信号强度(Received Signal Strength,RSS)的三维可见光定位(Visible Light Position,VLP)算法获得定位数据,同时估计信道状态信息(Channel State Information,CSI)并上传给发射端进行定向通信.该系统的发射端基于空移键控(Space Shift Keying,SSK)的室内可见光通信(Visible Light Communication,VLC)技术实现系统的通信功能.另外,本方案可以完全避免通信与定位子系统之间的干扰.同时,通过推导定位误差的克拉美罗下界(Cramér-Rao Lower Bound,CRLB)和SSK-VLC的通信可达速率来评估本文提出的VLPC系统的性能.仿真结果验证了本文所提方案的有效性.