scholarly journals Multiple-Symbol Differential Detection for Spatial Modulation

2016 ◽  
Vol 5 (1-2) ◽  
Author(s):  
Thu Phuong Nguyen ◽  
Minh Tuan Le ◽  
Xuan Nam Tran
Keyword(s):  
Error Probability ◽  
Signal To Noise Ratio ◽  
Observation Interval ◽  
Coherent Detection ◽  
Spatial Modulation ◽  
Differential Detection ◽  
Arbitrary Length ◽  
Sequence Detection ◽  
Symbol Detection ◽  
Maximum Likelihood Sequence Detection

Approximately 3 dB Signal-to-Noise Ratio (SNR) loss is always paid with conventional Differential Spatial Modulation (DSM) as compared to coherent Spatial Modulation (SM). In this paper, a Multiple-Symbol Differential Detection (MSDD) technique is proposed for DSM systems to mitigate the loss due to differential detection. The new scheme can greatly narrow the 3 dB performance gap by extending the observation interval for differential decoding. The technique uses maximum-likelihood sequence detection instead of traditional symbol-by-symbol detection, and is carried out on the slow, flat Rayleigh fading channel. A generalized decision metric is derived for an observation interval of arbitrary length. It is shown that for a moderate number of symbols, MSDD provides approximately 1.5 dB performance improvement over the conventional differential detection. In addition, a closed-form pairwise error probability and approximate bit error probability (BEP) are derived for multiple-symbol differential spatial modulation. Results show that the theoretical BEP matches well the simulated one. The BEP is shown to converge asymptotically with the number of symbols in the observation interval to that of the differential scheme with coherent detection.

scholarly journals On the Performance Analysis of Switched Diversity Combining Receivers over Fisher–Snedecor ℱ Composite Fading Channels

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3014
Author(s):  
Weijun Cheng ◽  
Xiaoting Wang ◽  
Tengfei Ma ◽  
Gang Wang
Keyword(s):  
Fading Channels ◽  
Error Probability ◽  
Signal To Noise Ratio ◽  
Multipath Fading ◽  
Performance Criteria ◽  
Statistical Characteristics ◽  
Diversity Combining ◽  
Systematic Analysis ◽  
Average Bit Error Probability ◽  
Switched Diversity Combining

In some emerging wireless applications, such as wearable communication and low-power sensor network applications, wireless devices or nodes not only require simple physical implementation approaches but also require certain reliable receiver techniques to overcome the effects of multipath or shadowed fading. Switched diversity combining (SDC) systems could be a simple and promising solution to the above requirements. Recently, a Fisher–Snedecor ℱ composited fading model has gained much interest because of its modeling accuracy and calculation tractability. However, the performance of SDC systems over ℱ fading channels has not yet been analyzed in the open literature. To this end, this paper presents a systematic analysis of SDC systems over ℱ fading channels, including dual-branch switch-and-stay combining (SSC), multibranch switch-and examine combining (SEC), and SEC with post-examining selection (SECps) systems. We first investigate the statistical characteristics of univariate and bivariate ℱ distributions. Then, these statistical expressions are introduced into the above SDC systems and the statistical metrics of the output signal-to-noise ratio (SNR) for these systems are deduced in different ℱ fading scenarios. Thirdly, certain exact and novel expressions of performance criteria, such as the outage probability, the average bit error probability and average symbol error probability, as well as the average channel capacity for SSC, SEC, and SECps are derived. To find the optimum performance, optimal analysis is performed for the independent and identically distributed cases. Finally, numerical evaluation and simulations are carried out to demonstrate the validity of the theoretical analysis under various ℱ fading scenarios. According to the obtained results, the multipath fading parameter has more influence on the performance of SDC systems than the shadowing parameter, the correlation coefficient, or the average SNR. Importantly, the SDC systems can provide switched diversity gains only when the switching threshold is not too large or too small compared to the average SNR.

scholarly journals A New Multiple-Symbol Differential Detection Strategy for Error-Floor Elimination of IEEE 802.15.4 BPSK Receivers Impaired by Carrier Frequency Offset

2019 ◽  
Vol 2019 ◽  
pp. 1-26 ◽  
Author(s):  
Gaoyuan Zhang ◽  
Congzheng Han ◽  
Baofeng Ji ◽  
Congyu Shi ◽  
Ping Xie ◽  
...  
Keyword(s):  
Spread Spectrum ◽  
Carrier Frequency ◽  
Ieee 802.15.4 ◽  
Carrier Frequency Offset ◽  
Frequency Offset ◽  
Coherent Detection ◽  
Differential Detection ◽  
Error Floor ◽  
Detection Strategy ◽  
Spectrum Coding

In this paper, we pay our attention towards the noncoherent demodulation aspect of binary phase shift keying (BPSK) receivers for IEEE 802.15.4 wireless sensor networks (WSNs), and a carrier frequency offset invariant as well as error-floor free multiple-symbol differential detection (MSDD) strategy is proposed over the flat fading channel. This detector is an alternative to the multiple-symbol detector that has been considered almost exclusively in the past. In this new configuration, the receivers do not perform chip-level precompensation as in conventional scheme but bit-level postcompensation. That is, the bit-level autocorrelation operation is first implemented with the “raw” chip sample, and then the carrier frequency offset effect (CFOE) embedded in the achieved statistic is compensated. Correspondingly, the cumulative error in the detection metric is decreased so much that the pervasive error floor for the conventional MSDD scheme is suppressed. Also, complexity efficient estimators for the MSDD scheme are reinvestigated, analyzed, and summarized. Simulation results demonstrate that this new detection strategy may achieve rather more encouraging gain from differential and spread spectrum coding than the conventional single differential coherent detection (SDCD) scheme. The pervasive error floor is also eliminated as compared with conventional MSDD scheme even if the most simple estimator is configured under large bit observation length. Then, much transmitting energy may be saved for each chip symbol, which is practically desired for transmit-only nodes in WSNs.

scholarly journals Optical spatial modulation design

2020 ◽  
Vol 378 (2169) ◽  
pp. 20190195 ◽  
Author(s):  
T. Cogalan ◽  
H. Haas ◽  
E. Panayirci
Keyword(s):  
Mimo Systems ◽  
Direct Detection ◽  
Signal To Noise Ratio ◽  
Multiple Input Multiple Output ◽  
Pulse Amplitude ◽  
Visible Light Communication ◽  
Performance Model ◽  
Spatial Modulation ◽  
Error Performance ◽  
Led Array

Visible light communication (VLC) systems are inherently signal-to-noise ratio (SNR) limited due to link budget constraints. One favourable method to overcome this limitation is to focus on the pre-log factors of the channel capacity. Multiple-input multiple-output (MIMO) techniques are therefore a promising avenue of research. However, inter-channel interference in MIMO limits the achievable capacity. Spatial modulation (SM) avoids this limitation. Furthermore, the performance of MIMO systems in VLC is limited by the similarities among spatial channels. This limitation becomes particularly severe in intensity modulation/direct detection (IM/DD) systems because of the lack of phase information. The motivation of this paper is to propose a system that results in a multi-channel transmission system that enables reliable multi-user optical MIMO SM transmission without the need for a precoder, power allocation algorithm or additional optics at the receiver. A general bit error performance model for the SM system is developed for an arbitrary number of light-emitting diodes (LEDs) in conjunction with pulse amplitude modulation. Based on this model, an LED array structure is designed to result in spatially separated multiple channels by manipulating the transmitter geometry. This article is part of the theme issue ‘Optical wireless communication’.

scholarly journals Upper Bound on the Bit Error Probability of Systematic Binary Linear Codes via Their Weight Spectra

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jia Liu ◽  
Mingyu Zhang ◽  
Chaoyong Wang ◽  
Rongjun Chen ◽  
Xiaofeng An ◽  
...  
Keyword(s):  
Upper Bound ◽  
Error Probability ◽  
Linear Codes ◽  
Signal To Noise Ratio ◽  
Additive White Gaussian Noise ◽  
High Signal ◽  
Binary Linear Codes ◽  
Enumerating Function ◽  
Bit Error Probability ◽  
Better Than

In this paper, upper bound on the probability of maximum a posteriori (MAP) decoding error for systematic binary linear codes over additive white Gaussian noise (AWGN) channels is proposed. The proposed bound on the bit error probability is derived with the framework of Gallager’s first bounding technique (GFBT), where the Gallager region is defined to be an irregular high-dimensional geometry by using a list decoding algorithm. The proposed bound on the bit error probability requires only the knowledge of weight spectra, which is helpful when the input-output weight enumerating function (IOWEF) is not available. Numerical results show that the proposed bound on the bit error probability matches well with the maximum-likelihood (ML) decoding simulation approach especially in the high signal-to-noise ratio (SNR) region, which is better than the recently proposed Ma bound.

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