An Effective Scheme of M-Ary Spread Spectrum System Based on Orthogonal Spread Spectrum and CPSK

2013 ◽  
Vol 765-767 ◽  
pp. 2696-2700
Author(s):  
Yue Xuan Liu ◽  
Shu Jian Liang ◽  
Yue Huai Ma ◽  
Song Xian Gong
Keyword(s):  
Monte Carlo Simulation ◽  
Bit Error Rate ◽  
Spread Spectrum ◽  
Bandwidth Efficiency ◽  
Transform Domain ◽  
Communication Scheme ◽  
System Synchronization ◽  
Orthogonal Spread ◽  
Simulation Results ◽  
Ber Performance

A hybrid M-ary spread spectrum (SS) communication scheme which combined with orthogonal SS and CPSK technique is proposed. Based on dual orthogonal SS, every SS code is treated as original code to adopt CPSK modulation, the unattached synchronous code is chosen to achieve system synchronization. At the receiver, A circular correlator based on transform domain processing is employed to de-spread the received signals. Compared with M-ary SS and CPSK, the proposed scheme is able to obtain higher bandwidth efficiency, stronger anti-intercept capability, and better synchronous performance. The Monte-Carlo simulation results demonstrate that the proposed scheme can achieve better synchronous and bit error rate (BER) performance under additional white gauss noise channel models.

scholarly journals 5G UFMC Scheme Performance with Different Numerologies

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1915
Author(s):  
Lambros Sakkas ◽  
Eleftherios Stergiou ◽  
Georgios Tsoumanis ◽  
Constantinos T. Angelis
Keyword(s):  
Mobile Communications ◽  
Bit Error Rate ◽  
Communication Systems ◽  
Modulation Scheme ◽  
Fifth Generation ◽  
Data Rates ◽  
The World ◽  
Simulation Results ◽  
5G Systems ◽  
Ber Performance

5G is the latest mobile communications standard that is spreading fast across the world. Recently defined requirements for 5G systems have led to higher applications’ requirements regarding data rates, lower requirements for latency, and higher efficiency regarding the spectrum usage. Universal Filtered Multi-Carrier (UFMC) is one new candidate modulation scheme for emergent Fifth Generation (5G) communication systems. This paper focuses on Universal Filtered Multi-Carrier (UFMC) design aspects in terms of Bit Error Rate (BER) performance in relation to the filter length used in subband filtering. Simulation results show that BER and CCDF performance varies for different filter lengths and modulation schemes. The main achievement of this work is that the results show that different Dolph–Chebyshev FIR filter lengths do not affect the BER performance both for the 64 and 256 QAM.

scholarly journals Efficient TTI for 3G Multimedia Applications

2007 ◽  
Vol 2007 ◽  
pp. 1-7 ◽  
Author(s):  
Costas Chaikalis
Keyword(s):  
Computational Complexity ◽  
Bit Error Rate ◽  
Fading Channel ◽  
Rayleigh Fading ◽  
Turbo Coding ◽  
Operating Environments ◽  
Data Rates ◽  
Simulation Results ◽  
Flat Rayleigh Fading ◽  
Ber Performance

Time transmission interval (TTI) or outer block interleaving is an important task for the implementation of UMTS turbo coding in flat Rayleigh fading environment. An efficient TTI choice can save computational complexity. However, different multimedia scenarios are investigated using the maximum UMTS frame length, and simulation results are presented for the four possible outer block interleaver configurations in the case of flat Rayleigh fading channel. It is shown that different operating environments require an appropriate TTI in terms of bit error rate (BER) performance for the following data rates: 28.8 kbps, 64 kbps, 144 kbps, 384 kbps, and 2 Mbps.

Beamforming with Kerdock Codes in LTE System for High-Speed Railway

2014 ◽  
Vol 989-994 ◽  
pp. 3556-3560
Author(s):  
Zhi Hua Yang ◽  
Lei Jun Wang ◽  
Ze Kai Fang
Keyword(s):  
Bit Error Rate ◽  
Communication System ◽  
System Performance ◽  
High Speed ◽  
High Speed Railway ◽  
Kerdock Codes ◽  
Simulation Results ◽  
Complex Multiplications ◽  
Beamforming Technique ◽  
Ber Performance

Beamforming technique based the reciprocity of LTE communication system for high-speed railway is a practical way to improve the system performance in this paper. Kerdock codes, which facilitate efficient codebook and codeword search, are implemented in the LTE system for high-speed railway as the beamforming precoding codebook. The analysis of complexity and simulation results about the communication system of the beamforming with Kerdock codes (KBF) show that the proposed KBF can eliminate complex multiplications and improve the Bit Error Rate (BER) performance at large SNR compared with the existing beamfoming communication system for high-speed railway.

scholarly journals On Narrowband Interference Suppression in TDCS with WFRFT Preprocessing

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Quan Wang ◽  
Xinxi Feng ◽  
Yuan Liang
Keyword(s):  
Bit Error Rate ◽  
Gaussian Noise ◽  
Fractional Fourier Transform ◽  
Additive White Gaussian Noise ◽  
Basic Function ◽  
Transform Domain ◽  
Narrowband Interference ◽  
Time Frequency ◽  
Relationship Coefficient ◽  
Ber Performance

We propose a modified transform domain communication system (TDCS) structure with weighted fractional Fourier transform (WFRFT) preprocessing over the channel with additive white Gaussian noise (AWGN) and narrowband interference (NBI). The majority of NBI can be removed by adding zeros to TDCS’s basic function (BF) amplitude vector at these subcarriers where strong NBI exists, and the corresponding residual NBI can be further greatly eliminated in time-frequency domain through WFRFT processing. To achieve the best bit error rate (BER) performance, we defineγas the normalised cross relationship coefficient between TDCS’s BF vector and residual NBI vector and prove that the corresponding WFRFTαoptcan be obtained by minimising the magnitude ofγ. Numerical simulations are conducted to evaluate the proposed system’s performance with regard to NBI suppression.

Performance Analysis of Duobinary and AMI Techniques Using LG Modes in Hybrid MDM-WDM-FSO Transmission System

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhenlei Zhou ◽  
Erkai Li ◽  
Haiguang Zhang
Keyword(s):  
Performance Analysis ◽  
Wavelength Division Multiplexing ◽  
Bit Error Rate ◽  
Error Rate ◽  
Optical Communications ◽  
Free Space Optical ◽  
Wavelength Division ◽  
Mode Division Multiplexing ◽  
Simulation Results ◽  
Ber Performance

AbstractThis work is focused on transmission of duobinary and alternate mark inversion (AMI) modulation, adopting mode division multiplexing (MDM) of Laguerre Gaussian (LG) modes has been capitalized in wavelength division multiplexing (WDM) system, resulting in a 1.6 Gbps eight-channel free space optical communications (FSO) system. The simulation results show that duobinary offers better bit error rate (BER) performance compared to AMI for proposed hybrid MDM-WDM-FSO system.

scholarly journals Protection scheme of subcarrier index in OFDM with index modulation aided by LDPC coding

2021 ◽  
Vol 39 (4) ◽  
pp. 818-823
Author(s):  
Yongjia Zhu ◽  
Yuyao He ◽  
Ye Fan ◽  
Rugui Yao
Keyword(s):  
Monte Carlo Simulation ◽  
Bit Error Rate ◽  
Fading Channel ◽  
Detection Algorithm ◽  
Spectrum Efficiency ◽  
Activation Pattern ◽  
Protection Scheme ◽  
Log Likelihood ◽  
Index Modulation ◽  
Ber Performance

The receiver of OFDM with Index Modulation (OFDM-IM) usually adopts a Log Likelihood Ratio (LLR) detection algorithm based on the activation state of subcarriers. However, the LLR detection algorithm will cause detection errors in subcarrier activation pattern (SAP) or get illegal SAP. Consequently, further errors occur in demodulation, increasing the bit error rate (BER). To solve this problem, we propose the protection scheme of subcarrier index aided by LDPC coding, which reduces the SAP detection errors by encoding the index information bits. On the receiver, the LDPC Coding Aided (LA) detection algorithm is designed, and the formula of LLR of index information bits is derived in detail. Monte Carlo simulation is carried out over multi-path fading channel by MATLAB software. The results show that under the condition that the spectrum efficiency is not lower than the classical OFDM-IM scheme, the proposed protection scheme can obtain a gain of about 5~9 dB when the BER is 10-4, effectively improving the BER performance of OFDM-IM scheme.

scholarly journals BER-Aware Reflecting Elements Allocation for RIS-aided NOMA Networks over Ricean Fading

2022 ◽  
Author(s):  
Krisma Asmoro ◽  
I Nyoman Apraz Ramatryana ◽  
Soo Young Shin
Keyword(s):  
Objective Function ◽  
Bit Error Rate ◽  
Multiple Access ◽  
Rayleigh Fading ◽  
Exhaustive Search ◽  
Search Range ◽  
Ricean Fading ◽  
Simulation Results ◽  
Average User ◽  
Ber Performance

Reconfigurable intelligent surface (RIS) as a supportive technology for aiding downlink non-orthogonal multiple access (NOMA) can enhance the bit error rate (BER) performance. In this paper, a novel BER-aware reflecting elements allocation (REA) on an RIS is proposed to maintain the BER order among paired RIS-NOMA users. The RIS REA is useful for minimizing the average user BER, ompared with a system that allocates the same number of elements to all users. Additionally, the Ricean fading is considered instead of Rayleigh fading as it is more practical and general. Furthermore,an REA optimization objective function for equalizing the user BER is proposed. In order to solve the problem, a modified exhaustive search is proposed to reduce complexity. The distribution of the objective function is observed first; subsequently, the exhaustive search range is determined. Both the analytical and simulation results show that the proposed algorithm can minimize the average user BER.

Performance Analysis of Duobinary and CSRZ Modulation Based Polarization Interleaving for High-Speed WDM-FSO Transmission System

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhenlei Zhou ◽  
Haiguang Zhang ◽  
Chun Lin ◽  
Abhishek Sharma
Keyword(s):  
Wavelength Division Multiplexing ◽  
Bit Error Rate ◽  
Optical Communications ◽  
High Speed ◽  
Transmission System ◽  
Free Space Optical ◽  
Wavelength Division ◽  
Simulation Results ◽  
Pi System ◽  
Ber Performance

AbstractIn this paper, the bit error rate (BER) performance of Duobinary (DB) is compared with carrier-suppressed return-to-zero (CSRZ) based polarization interleaving (PI) schemes for high-speed transmission system. The system is integrated with wavelength-division multiplexing (WDM) scheme and PI scheme for free space optical communications (FSO). The simulation results show that DB offers betters BER performance compared to CSRZ in high-speed WDM-FSO-PI system.

A Multiaddress Co-Chaos Shift Keying Communication Scheme and Performance Analysis

2014 ◽  
Vol 24 (04) ◽  
pp. 1450050
Author(s):  
Zhiliang Zhu ◽  
Jingping Song ◽  
Yanjie Song ◽  
Hai Yu
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Gaussian White Noise ◽  
Transmission Efficiency ◽  
Theory Analysis ◽  
Shift Keying ◽  
Communication Scheme ◽  
Simulation Results ◽  
And Performance ◽  
Chaos Shift Keying

A new multiaddress Co-Chaos Shift keying communication scheme (MA-CoCSK) was proposed based on analyzing the permutation-based differential chaos-shift-keying (PMA-DCSK) scheme and the Antipodal Chaos-Shift-Keying (ACSK) scheme. We also analyzed the bit error rate of the new scheme in Gaussian white noise channel and compared its performance with that of the PMA-DCSK scheme. Theory analysis and simulation results both indicate that the scheme proposed in this paper can not only improve the transmission efficiency of a communication system, but also decrease the bit error rate significantly while increasing the speed compared to PMA-DCSK.

SDR-Based Precoding for Multi-User Multi-Stream MIMO Downlinks

2014 ◽  
Vol 543-547 ◽  
pp. 2004-2008
Author(s):  
Xin Min Li ◽  
Bao Ming Bai ◽  
Juan Zhao
Keyword(s):  
Bit Error Rate ◽  
Optimization Problem ◽  
Optimization Theory ◽  
Threshold Value ◽  
Low Complexity ◽  
Semidefinite Programs ◽  
Single Antenna ◽  
Simulation Results ◽  
Quadratically Constrained ◽  
Ber Performance

The existing methods based on convex-optimization theory, which use the concept of SINR, can just design the optimal precoder for each user with single antenna. In this paper, we design the optimal precoding matrices for multi-user MIMO downlinks by solving the optimization problem that minimizes total transmit power subject to signal-leakage-plus-noise-ratio (SLNR) constraints. Because SLNR of each user is determined by its own precoding matrix and is independent of other users, the goal problem can be separated into a series of decoupled low-complexity quadratically constrained quadratic programs (QCQPs). Using the semidefinite relaxation (SDR) technique, these QCQPs can be reformulated into the semidefinite programs (SDP) and be solved effectively. Simulation results show that proposed precoding scheme is quite feasible when each user has two receive antennas, and it has better bit error rate (BER) performance than the original maximal-SLNR precoding scheme when SLNR of each user satisfies large threshold value.

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