Multiple Phase Shift Keying Research Articles

Two-Transmitter Two-Receiver Cooperative MAC Protocol: Cross-Layer Design and Performance Analysis

Cooperative diversity is a promising and practical technique for realizing spatial diversity through a virtual antenna array formed by multiple distributed antennas of different nodes. In this paper, we propose and evaluate a novel cooperative cross-layer medium access control (CC-MAC) protocol, which combines space-time coding and adaptive modulation at the physical layer and employs truncated automatic repeat request (ARQ) at the data-link layer. The transmitter's partner is selected in the previous hop, and the receiver invites a partner to participate in data reception in the current hop, and in this situation, a two-transmitter two-receiver model is constructed. Because distributed space-time coding is applied at the transmitting set (transmitter and its partner), cooperative diversity and coding gain can be obtained. Based on the instantaneous channel state measured at the receiver, an adaptive modulation scheme is adopted to improve the link throughput at the physical layer. In addition, the truncated ARQ scheme is employed to further enhance the throughput performance at the data-link layer. Furthermore, under different system models with or without the truncated ARQ scheme, performances of the average packet error rate (PER) and symbol error rate (SER) with multiple phase shift keying (M-PSK) modulation and multiple quadrature amplitude modulation (M-QAM) over Rayleigh fading channel are analyzed. Simulation results verify the correctness of the performance analysis and show that CC-MAC can significantly improve system throughput and energy efficiency compared with other transmission schemes.

Constellation labeling maps for low error floors

A constellation labeling map is the assignment of a bit pattern to each symbol in a signal-set constellation. In a system with iterative decoding and demodulation, the error floor of the bit error rate is highly dependent on the labeling map. A simple class of labeling maps that significantly lower the error floors is presented. Examples show the applications of the proposed mapping to multiple phase-shift keying (MPSK), quadrature amplitude modulation (QAM), and continuous-phase frequency-shift keying (CPFSK). Simulation results indicate that the proposed labeling maps are comparable to or better than other labeling maps in providing a low error floor. A major advantage of the proposed labeling maps is that they are easily generated even when the alphabet size is large.

BER analysis of MPSK space-time code with differential detection over correlated block-fading Rayleigh channel

MIMO technology proposed in recent years can effectively combat the multipath fading of wireless channel and can considerably enlarge the channel capacity, which has been investigated widely by researchers. However, its performance analysis over correlated block-fading Rayleigh channel is still an open and challenging objective. In this article, an analytic expression of bit error rate (BER) is presented for multiple phase shift keying (MPSK) space-time code, with differential detection over correlated block-fading Rayleigh channel. Through theoretical analysis of BER, it can be found that the differential space-time scheme without the need for channel state information (CSI) at receiver achieves distinct performance gain compared with the traditional nonspace-time system. And then, the system simulation is complimented to verify the above result, showing that the diversity system based on the differential space-time block coding (DSTBC) outperforms the traditional nonspace- time system with diversity gain in terms of BER. Furthermore, the numerical results also demonstrate that the error floor of the differential space-time system is much lower than that of the differential nonspace-time system.

Induced [formula omitted]-norm FIR filter for recovering MPSK-type modulus signals

This paper proposes a method of perfectly recovering MPSK-type (multiple phase-shift keying) modulus input signals against component-wise norm-bounded disturbances via an induced ∞ -norm finite impulse response (FIR) filter. The induced ∞ -norm criterion maintains the distance between the input signals and the estimated signals within a given bound for perfectly recovering the input signals, and the FIR structure makes the system robust against temporary uncertainties or disturbances. The induced ∞ -norm FIR filter is designed through solving linear matrix inequalities (LMIs) iteratively. Examples of the application to equalizers show that the induced ∞ -norm FIR filter guarantees the perfect recovery of the MPSK-type modulus input signals.

On the Relation Between the Amplitude Probability Distribution of Noise and Bit Error Probability

In the paper entitled "Relation Between the Amplitude Probability Distribution of an Interfering Signal and Its Impact on Digital Radio Receivers," a formula for estimating the bit error probability of an interfered digital wireless receiver was presented in terms of the amplitude probability distribution of the noise. This formula is very useful for predicting the impact of interfering signals on digital wireless systems and for defining appropriate limits for the interfering signal level to protect wireless systems. However, the formula must be corrected so that it is valid for modulation schemes, such as quadratic-amplitude modulation and multiple phase-shift keying.

Closed-form error rates of STBC systems and its performance analysis

The closed-form solutions for error rates of Space-Time Block Code (STBC) Multiple Phase Shift Keying (MPSK) systems are derived in this paper. With characteristic function based method and the partial integration based respectively, the exact expressions of error rates are obtained for (2,1) STBC with and without channel estimation error. Simulations show that the practical error rates accord with the theoretical ones, so closed-form error rates are accurate references for STBC performance evaluation. For the error of pilot assisted channel estimation, the performance of a (2,1) STBC system is deteriorated about 3dB.

Quasi-orthogonal STBC with minimum decoding complexity

In this paper, we consider a quasi-orthogonal (QO) space-time block code (STBC) with minimum decoding complexity (MDC-QO-STBC). We formulate its algebraic structure and propose a systematic method for its construction. We show that a maximum-likelihood (ML) decoder for this MDC-QO-STBC, for any number of transmit antennas, only requires the joint detection of two real symbols. Assuming the use of a square or rectangular quadratic-amplitude modulation (QAM) or multiple phase-shift keying (MPSK) modulation for this MDC-QO-STBC, we also obtain the optimum constellation rotation angle, in order to achieve full diversity and optimum coding gain. We show that the maximum achievable code rate of these MDC-QO-STBC is 1 for three and four antennas and 3/4 for five to eight antennas. We also show that the proposed MDC-QO-STBC has several desirable properties, such as a more even power distribution among antennas and better scalability in adjusting the number of transmit antennas, compared with the coordinate interleaved orthogonal design (CIOD) and asymmetric CIOD (ACIOD) codes. For the case of an odd number of transmit antennas, MDC-QO-STBC also has better decoding performance than CIOD.

Symbol-Error Probability and Bit-Error Probability for Optimum Combining With MPSK Modulation

New expressions are derived for the exact symbol error probability and bit-error probability for optimum combining with multiple phase-shift keying. The expressions are for any numbers of equal-power cochannel interferers and receive branches. It is assumed that the aggregate interference and noise is Gaussian and that both the desired signal and interference are subject to flat Rayleigh fading. The new expressions have low computational complexity, as they contain only a single integral form with finite limits and finite integrand.

Differentially coherent communication with multiple-symbol observation 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).

Clock multiplier using digital CMOSstandard cells for high-speed digitalcommunication systems

The authors propose and evaluate the performance of a 2N times clock multiplier that controls memory components for high-speed data communications. To improve the reliability of the circuit, a symmetric circuit structure is used, while to verify circuit operation by means of a simple method, an MVU estimator is found from simulation data. The proposed circuit can provide clock rates, which are usually required in the multiple phase shift keying (MPSK) or multiple quadrature amplitude modulation (MQAM) modulation schemes, of 2 to 2N times that of the input clock.

Analysis of switched diversity TCM-MPSK systems on Nakagami fading channels

Space diversity reception and forward-error correction coding are powerful techniques to combat multipath fading encountered in mobile radio communications. In this paper, we analyze the performance of a discrete-time switched diversity system using trellis-coded modulation multiple phase-shift keying (TCM-MPSK) on slow, nonselective correlated Nakagami (1960) fading channels. Analytical upper bounds using the transfer function bounding technique are obtained and illustrated by several numerical examples. A simple integral expression for calculating the exact pairwise error probability is presented. The use of optimum adaptive and fixed switching thresholds is considered. Monte Carlo simulation results, which are more indicative of the exact system performance, are also given.

Multidimensional M-PSK trellis codes for fading channels

This paper investigates the code search problem for trellis-coded multidimensional phase modulation for Rayleigh fading channels. New set partitionings for multiple phase-shift keying (M-PSK) are proposed using the effective code length (ECL) and the minimum product distance (PD) as the code design criteria. By using these set-partitionings rules, new multidimensional codes which are optimum for Rayleigh fading channels are constructed. The proposed codes compare favorably with the existing multidimensional trellis codes on fading channels in terms of bit error performance. The bit error performance is evaluated by simulation.

The impact of Rayleigh backscatter induced noise on QPSK transmission with Fabry-Perot lasers

The use of uncooled Fabry-Perot (FP) lasers for upstream data in cable television (CATV) networks has recently been proposed. The merits of this choice, from use in telecommunications networks, include low cost and proven reliability. Indeed, it has been shown that these devices can transmit multiple quadrature phase shift keying (QPSK) signals in an error-free manner. However, there is a bit-error-rate (BER) penalty associated with these lasers, that impacts the useable error free range. We show this degradation is caused by laser sporadic noise generated by Rayleigh backscatter into the laser from the fiber plant. In addition, we show the noise to be impulsive and that a 14 dB CNR penalty, at 1/spl times/10/sup -8/ BER, versus theoretical performance is possible.

Multiple-symbol differential detection of MPSK

A differential detection technique for MPSK (multiple-phase shift keying), which uses a multiple-symbol observation interval, is presented, and its performance is analyzed and simulated. The technique makes use of maximum-likelihood sequence estimation of the transmitted phases rather than symbol-by-symbol detection as in the conventional differential detection. Thus, the performance of this multiple-symbol detection scheme fills the gap between conventional (two-symbol observation) differentially coherent detection of MPSK and ideal coherent of MPSK with differential encoding. The amount of improvement gained over conventional differential detection depends on the number of phases M and the number of additional symbol intervals added to the observation. What is particularly interesting is that substantial performance improvement can be obtained for only one or two additional symbol intervals of observation. The analysis and simulation results presented are for uncoded MPSK.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The performance of trellis-coded MDPSK with multiple symbol detection

The idea of using a multiple (more than two) symbol observation interval to improve error probability performance is applied to differential detection of trellis-coded multiple phase-shift keying (MPSK) over an additive white Gaussian noise (AWGN) channels. An equivalent Euclidean distance measure per trellis branch is determined for this detection scheme. This is used to define an augmented (larger multiplicity) trellis code whose distance measure is the conventional squared Euclidean distance typical of conventional trellis-coded modulation on the AWGN. Such an augmented multiple trellis code is a convenient mathematical tool for simplifying the analysis. Results are obtained by a combination of analysis and computer simulation. It is shown that only a slight increase (e.g. one symbol) in the length of the observation interval will provide a significant improvement in bit error probability performance. >

Multiple trellis coded modulation (MTCM)

The authors demonstrate a trellis coded modulation technique referred to as multiple trellis coded modulation (MTCM) wherein more than one channel symbol per trellis branch is transmitted. They have found simple two-state trellis codes for symmetric MPSK multiple phase-shift keying and AM modulations that can achieve 3-dB gain over uncoded modulation at very high signal-to-noise ratios without bandwidth expansion or reduction in information bit rate. The gain of these codes with respect to previously reported two-state trellis codes is between 1 and 2 dB at very high signal-to-noise ratios, depending on the number of bits per Hertz transmitted. These gains are achieved for those of the equivalent conventional trellis codes with the same number of states in the trellis diagram. The authors note that additional computations per branch are needed for the multiple trellis coding scheme. The concept can be extended to a higher number of states and other types of modulations. >