Probability of error analysis of digital partial responsecontinuous phase modulation with noncoherent detection in mobile radiochannels

An analysis is presented of noncoherent detection of constant-envelope digital partial-response continuous-phase modulation (PRCPM) in fast Rayleigh fading that characterizes land mobile radio channels. Closed-form expressions for the probability of error are derived for limiter discriminator detection, and both 1- and 2-bit differential detection. Numerical results are presented for cases of practical interest to researchers and designers of land mobile radio systems. The expressions derived for the probability of error are general and can be used for all PRCPM schemes     

Probability of error analysis of digital partial responsecontinuous phase modulation with two-bit differential detection andoffset receiver diversity in fast Rayleigh fading channels

The performance of constant envelope digital partial response continuous phase modulation (PRCPM) with two-bit differential detection and offset receiver diversity is theoretically analyzed in fast Rayleigh fading channels. A simple closed-form expression for the probability of error is derived and evaluated for cases of practical interest to researchers and designers of land mobile radio systems. It is shown that the dynamic bit error rate (BER) performance is considerably improved using the offset diversity scheme. Thus, many PRCPM signals having a compact power spectrum can be used in future digital mobile radio systems     

两元相位光栅光调制

基于两元相位光栅的自成像效应和相位补偿的原理,本文提出了两元光学的一种新的双相位光栅光调制器。用菲涅耳衍射理论导出了任意光束的解析解,进行了高斯光束的计算机模拟。表明调制度正比于光束直径而反比于两光栅的间距,最后给出了实验。     

Differentially coherent communication with multiple-symbolobservation interval

A novel differential detection technique for multiple phase shift keying (MPSK), which uses multiple-symbol observation interval, is proposed and its performance is analyzed. The proposed technique detects the transmitted symbol with accumulation of the differential signal vector projected on the previously received symbol. As with the multiple-symbol differential detection (MSDD) technique, the performance of the proposed scheme fills the gap between the conventional differential and the ideal coherent detection. The amount of improvement depends on the number of phases M and the number of additional symbol intervals N of observation. Performance analysis and simulation show considerable improvement with only 1 or 2 additional symbol intervals of observation. In addition, the complexity increases linearly with observation interval and is smaller than that of Divsalar and Simon (1990) and of Edbauer (1992)     

A partially coherent detector for continuous phase modulation

A novel partially coherent detector for joint data detection and carrier phase estimation of continuous-phase-modulated (CPM) signal is presented. The algorithm differs from coherent Viterbi algorithm only in the metric which it maximizes over the possible transmitted data sequences. This metric is influenced both by the correlation of the hypothesized signal with the received one and the current carrier phase estimate. The system has been simulated and comparisons made with existing detection techniques on channels with additive white Gaussian noise and carrier phase jitter. Simulations of the detector are used to assess the relative susceptibility of different CPM (continuous phase modulation) schemes to phase jitter. The trend is that narrower band schemes are more sensitive to carrier phase inaccuracy than the less spectrally efficient ones     

Optimum detection and signal selection for partially coherent binary communication

The optimum detectors for coherent and noncoherent reception of binary signals in additive Gaussian noise and the resuiting error probabilities were obtained by Helstrom [1]. In many practical communication systems a reasonable estimate of the phase of the received signal is available as the result of an auxiliary tracking operation of the carrier signal by a coherent tracking device such as a phase-locked loop. It is shown that the optimum detector for this case, which we refer to as partially coherent reception, is a linear combination of the correlation detector and the squared envelope correlation detector, which are optimum for the coherent and noncoherent cases, respectively. The error probabilities are also obtained as a function of the energy-to-noise ratio of the channel and the variance of the error in the phase estimate, which is a function of the signal-to-noise (SNR) in the tracking loop. The signal selection problem is considered in terms of these parameters.     

Simplified receiver design for STBC binary continuous phase modulation

Existing space-time codes have focused on multiple- antenna systems with linear modulation schemes such as phase- shift keying and quadrature amplitude modulation. Continuous phase modulation (CPM) is an attractive scheme for digital transmission because of its constant envelope which is needed for power efficient transmitters. Recent research has shown that space-time coded CPM can achieve transmit diversity to improve performance while maintaining the compact spectrum of CPM signals. However, these efforts mainly combine space- time coding (STC) with CPM to achieve spatial diversity at the cost of a high decoding complexity. In this paper, we design space-time block codes (STBC) for binary CPM with modulation index h = 1/2 and derive low-complexity receivers for these systems. The proposed scheme has a much lower decoding complexity than STC CPM with the Viterbi decoder and still achieves near-optimum error performances.     

Adaptive differentially coherent orthogonally multiplexed orthogonal phase modulation over flat fading channels

A constant-power adaptive transmission technique adopting differentially coherent orthogonally multiplexed orthogonal phase modulation (DOMOPM) signals is studied for flat fading channels. Numerical results show that the constant-power adaptive DOMOPM system significantly outperforms the constant-power adaptive noncoherent frequency shift keying system in average spectral efficiency.     

Serially concatenated continuous phase modulation with reduced iterative demodulation and detection

A reduced state Soft Input Soft Output （SISO） a posteriori probability algorithm for Serially Concatenated Continuous Phase Modulation （SCCPM） is proposed in this paper. Based on the Reduced State Sequence Detection （RSSD）, it has more general form compared with other reduced state SISO algorithms. The proposed algorithm can greatly reduce the state number, thus leads to the computation complexity reduction. It also minimizes the degradation in Euclidean distance with decision feedback in the reduced state trellis. Analysis and simulation results show that the performance degradation is little with proper reduction scheme.     

Effect of noisy phase reference on coherent detection ofband-limited offset-QPSK signals

The performance of bandlimited offset-quaternary-phase-shift-keying (OQPSK) systems in the presence of noisy phase reference and additive Gaussian noise is analyzed. Expressions for error probability calculation are obtained. A new search method for computing the detection loss and the required SNR of the phase reference is proposed. It is shown that when the rolloff factor for the Nyquist filtering is large, OQPSK surpasses QPSK, but when the rolloff factor is small, QPSK surpasses OQPSK     

Performance degradation due to cross-phase modulation in optical fdm ask coherent detection systems

The performance degradation due to cross-phase modulation in optical FDM ASK coherent detection systems has been investigated in this paper. The effect of modulation statistics and phase tracking of the receivers is taken into account. Based on the theoretical treatment, power penalty and allowable launched power per channel have been estimated.     

Algorithms of synchronization and detection of continuous-phase modulated signals with cyclically varying modulation index

Algorithms of simultaneous superbaud, clock, and phase synchronization for the detectors of continuous-phase modulated signals with cyclically varying modulation index are considered. The algorithms are based on the theory of nonlinear filtering and optimized with respect to the minimum mean-square error. A closed-loop model of the synchronization system is constructed and comprehensively studied with the aid of computer simulation.     

折射率相位调制型全息图的衍射

首先推出折射率相位调制型全息光栅的衍射方程,由此说明衍射效率主要取决于调制折射率,且各级衍射光的衍射效率不同是多种原因造成的。并指出体积光栅效应对透射全息衍射效率是有贡献的,讨论了影响散射物体全息衍射效率的问题,最后指出在一般情况下,调制折射率是一个很小的量,化学处理对它起着关键性的作用。     

MTBF of a complex binary coherent system

It is noted that there has yet been no detailed study of the relationships between the MTBF (mean time between failures) of a system and the sequences of component failures, except for the case of a series system where every component failure causes a system failure. The author defines MTBF anew and derives relationships between the properties of the MTBF of a binary coherent system and the properties of the sequences of component failures, assuming that the lifetime distributions of the components are either new-better-than-used (NBU) exponential or increasing failure rate (IFR). Lower bounds of MTBF that can be used to predict the MTBF and to decide whether the system would satisfy the MTBF requirement are derived     

Reduced state sequence detection of full response continuous phase modulation

A reduced state sequence detector (RSSD) which combines decision feedback with Viterbi decoding is proposed for M-ary full response continuous phase modulation. The detector is analysed with minimum Euclidean distances and by simulations of the symbol error probability. It is shown that M-ary full response CPM schemes can be optimally decoded by a decoder with only two states when the modulation index is relatively small (>     

Differentially coherent PN code acquisition with full-periodcorrelation in chip-synchronous DS/SS receivers

Differentially coherent detection techniques for PN code acquisition in direct-sequence spread-spectrum (DS/SS) receivers are designed and analyzed in this letter. The full-period cross correlation (FPC) can be modeled as deterministic for certain types of PN sequences whose autocorrelation functions have ideal shapes the same as those of maximum length shift registration (MLSR) sequences. This model is exploited here to simplify the design and performance evaluation of the proposed detection techniques. Such techniques can be confidently employed as alternatives to noncoherent detectors because of their attractive improvements in the signal-to-noise ratio (SNR) and, thus, are very suitable for commercial code-division multiple-access (CDMA) systems, which often operate in severely noisy environments. The results of statistical analyses show that the proposed techniques can provide rapid acquisition and improved performance in SNR     

Modelling of binary phase modulation in surface stabilized ferroelectric liquid crystal spatial light modulators

Modelling of binary phase modulation is required for optimal performance of ferroelectric liquid crystals (FLC) on silicon SLMs when used in coherent optical systems. This paper presents a modelling technique by which an HSpice model can be provided for characterization of phase modulation properties for designing FLC-on-silicon SLMs. The simulation and experimental measurements of phase modulation are described. For the theoretical model simulation, FLC parameter measurements are described. We experimentally verify the modelled prediction of phase modulation by investigating reflective FLC test cells. We have shown reasonable agreement within 9% between the measured and simulated values of phase modulation.     

Standing-wave EO phase modulator using nonperiodic domain inversionfor large modulation index

A deep microwave EO phase modulator using a standing-wave electrode structure together with nonperiodic domain inversion is presented. The calculation and experimental results show that the maximum modulation index obtained by this modulator is 30% higher than the best result obtained for a travelling-wave EO phase modulator with periodic domain inversion     

Multiuser detection for continuous phase modulation over Rayleigh fading channels

We study multiuser (MU) continuous phase modulation (CPM) over Rayleigh fading channels with a receiver antenna array. An optimum symbol-by-symbol MU detector is derived and its practical implementation with reduced-complexity is considered. According to the numerical results, the MU detector performs very close to a system free of interference by other users, when each user has more than one receiving antenna. For three receiving antennas, this difference is less than 0.25 dB, 0.4 dB, and 0.6 dB for two, three and four users, respectively. Moreover, the proposed system is bandwidth efficient as CPM is a bandwidth efficient modulation scheme, and the MU system only uses the single user CPM bandwidth.