scholarly journals Security Improvement in Next Generation Wireless System by Interleaver in Transceiver Structures

2017 ◽  
Author(s):  
B. Partibane ◽  
R. Kalidoss ◽  
R. Karthipan
Keyword(s):  
Interference Cancellation ◽  
Iterative Decoding ◽  
Channel Model ◽  
Minimum Mean Square Error ◽  
Antenna System ◽  
Posteriori Probability ◽  
Decoding Algorithm ◽  
Simulation Results ◽  
Dual Polarized ◽  
Dual Polarized Antenna

This paper presents the multiple-input multiple-output Interleave division multiple access (MIMO-IDMA) system with dual polarized division multiplexing (DPDM). Dual polarized antenna system replaces the uni-polarized antenna system availing cost and space features. We have considered dual- Polarized antennas at both the transmitter and the receiver ends to establish DPDM. For the purpose of accommodation, the users are separated with userspecific interleaver in combination with a low rate spreading sequence. In the receiver, we consider the minimum mean square error (MMSE) algorithm based successive interference cancellation (SIC) Multi-user detection (MUD) technique to diminish the effects of multi-stream interference (MSI). Furthermore, we implement Log-maximum a posteriori probability (MAPP) decoding algorithm at the mobile stations (MSs) to alleviate the effects of multi-user interference (MUI).We evaluate the effects of codedMIMO-IDMA system in the context of downlink (DL) communication pertaining to the Stanford University Interim (SUI) and Long-term Evolution (LTE) channel model specifications.We observe that our simulation results considered turbo coded Dual-PolarizedMIMO-IDMAsystem with iterative decoding algorithm provides a better bit error rate (BER) performance with less signal to noise ratio (SNR) when compared to uncoded system. Furthermore our simulation results show that MIMO-IDMA system with Dual-Polarized antenna requires higher SNR than uni-polarized antennas in order to achieve same BER. However, it provides the advantage of replacing two uni-polarized antennas by a single Dual-Polarized antenna which can therefore help achievement of a higher data rate with a reduced size of MS in the context of DL transmission.  

Dual-Path Dual-Polarized Antenna System for SDARS Application

2006 ◽  
Author(s):  
Young-pyo Hong ◽  
Jung-min Kim ◽  
Mun-ho Choi ◽  
Yongshik Lee ◽  
Jong-gwan Yook
Keyword(s):  
Antenna System ◽  
Dual Polarized ◽  
Dual Polarized Antenna

scholarly journals An Efficient Turbo Decoding and Frequency Domain Turbo Equalization for LTE Based Narrowband Internet of Things (NB-IoT) Systems

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5351
Author(s):  
Mohammed Jajere Adamu ◽  
Li Qiang ◽  
Rabiu Sale Zakariyya ◽  
Charles Okanda Nyatega ◽  
Halima Bello Kawuwa ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Turbo Codes ◽  
Channel Coding ◽  
Interference Cancellation ◽  
Minimum Mean Square Error ◽  
Turbo Equalization ◽  
Posteriori Probability ◽  
Turbo Decoding ◽  
A Posteriori Probability ◽  
Phy Layer

This paper addresses the main crucial aspects of physical (PHY) layer channel coding in uplink NB-IoT systems. In uplink NB-IoT systems, various channel coding algorithms are deployed due to the nature of the adopted Long-Term Evolution (LTE) channel coding which presents a great challenge at the expense of high decoding complexity, power consumption, error floor phenomena, while experiencing performance degradation for short block lengths. For this reason, such a design considerably increases the overall system complexity, which is difficult to implement. Therefore, the existing LTE turbo codes are not recommended in NB-IoT systems and, hence, new channel coding algorithms need to be employed for LPWA specifications. First, LTE-based turbo decoding and frequency-domain turbo equalization algorithms are proposed, modifying the simplified maximum a posteriori probability (MAP) decoder and minimum mean square error (MMSE) Turbo equalization algorithms were appended to different Narrowband Physical Uplink Shared Channel (NPUSCH) subcarriers for interference cancellation. These proposed methods aim to minimize the complexity of realizing the traditional MAP turbo decoder and MMSE estimators in the newly NB-IoT PHY layer features. We compare the system performance in terms of block error rate (BLER) and computational complexity.

scholarly journals Linear and Decoupled Decoders for Dual-Polarized Antenna-Based MIMO Systems

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7141
Author(s):  
Sara Shakil Qureshi ◽  
Sajid Ali ◽  
Syed Ali Hassan
Keyword(s):  
Channel Model ◽  
Mimo Systems ◽  
Design Parameters ◽  
Orthogonal Designs ◽  
Orthogonal Codes ◽  
Construction Techniques ◽  
Dual Polarized ◽  
Improved Performance ◽  
Diversity Gains ◽  
Dual Polarized Antenna

Quaternion orthogonal designs (QODs) have been used to design STBCs that provide improved performance in terms of various design parameters. In this paper, we show that all QODs obtained from generic iterative construction techniques based on the Adams-Lax-Phillips approach have linear and decoupled decoders which significantly reduce the computational complexity at the receiver. Our result is based on the quaternionic description of communication channels among dual-polarized antennas. Another contribution of this work is the linear and decoupled decoder for quasi-orthogonal codes for non-square as well as square designs. The proposed solution promises diversity gains with the quaternionic channel model and the decoding solution is independent of the number of receive dual-polarized antennas. A brief comparison is presented at the end to demonstrate the effectiveness of quaternion designs in two dual-polarized antennas over available STBCs for four single-polarized antennas. Linear and decoupled decoding of two quasi-orthogonal designs is shown, which has failed to exit previously. In addition, a QOD for 2×1 dual-polarized antenna configuration using quaternionic channel model shows a 3 dB gain at 10−5 in comparison to the same code evaluated for 2×2 complex representation of the quaternionic channel. This gain is further enhanced when the received diversity for these the cases is matched i.e., 2×2. The code using the quaternionic channel model shows a further 13 dB improvement at 10−5 BER.

S-band dual-path dual-polarized antenna system for satellite digital audio radio service (SDARS) application

2006 ◽  
Vol 54 (4) ◽  
pp. 1569-1575 ◽  
Author(s):  
Young-Pyo Hong ◽  
Jung-Min Kim ◽  
Soon-Chul Jeong ◽  
Dong-Hyun Kim ◽  
Mun-Ho Choi ◽  
...  
Keyword(s):  
Antenna System ◽  
Digital Audio ◽  
Dual Polarized ◽  
Dual Polarized Antenna

Quantization Methods of the Reliability-Based Iterative Decoding Algorithm for LDPC Codes

2015 ◽  
Vol 738-739 ◽  
pp. 699-704
Author(s):  
Hai Qiang Chen ◽  
Ling Shan Luo ◽  
Xiao Li Huang ◽  
Dao Feng Li ◽  
Qi Liang ◽  
...  
Keyword(s):  
Convergence Rate ◽  
Iterative Decoding ◽  
Ldpc Codes ◽  
Slight Modification ◽  
Design Criterion ◽  
Parameter Design ◽  
Decoding Algorithm ◽  
Interval Probability ◽  
Uniform Quantization ◽  
Simulation Results

This paper investigates the quantization methods of the reliability-based iterative decoding algorithm for LDPC codes. For the uniform quantization, we present a new design criterion to determine the quantization parameters with the clipping interval/probability. Compared to the original parameters setting, the presented design criterion can achieve higher resolution with the allowable quantization distortions. The presented parameter design criterion can be extended to the non-uniform quantization with a slight modification. Simulation results show that, the decoding algorithm can achieve better BER performances and faster convergence rate with smaller quantization bit when compared to the original parameters setting.

scholarly journals Modeling of Downlink Interference in Massive MIMO 5G Macro-Cell

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 597
Author(s):  
Kamil Bechta ◽  
Cezary Ziółkowski ◽  
Jan M. Kelner ◽  
Leszek Nowosielski
Keyword(s):  
Power Distribution ◽  
Communication Systems ◽  
Channel Model ◽  
Radio Channel ◽  
Angular Separation ◽  
Simulation Method ◽  
Antenna System ◽  
Propagation Model ◽  
Simulation Results ◽  
The Impact

Multi-beam antenna systems are the basic technology used in developing fifth-generation (5G) mobile communication systems. In practical implementations of 5G networks, different approaches are used to enable a massive multiple-input-multiple-output (mMIMO) technique, including a grid of beams, zero-forcing, or eigen-based beamforming. All of these methods aim to ensure sufficient angular separation between multiple beams that serve different users. Therefore, ensuring the accurate performance evaluation of a realistic 5G network is essential. It is particularly crucial from the perspective of mMIMO implementation feasibility in given radio channel conditions at the stage of network planning and optimization before commercial deployment begins. This paper presents a novel approach to assessing the impact of a multi-beam antenna system on an intra-cell interference level in a downlink, which is important for the accurate modeling and efficient usage of mMIMO in 5G cells. The presented analysis is based on geometric channel models that allow the trajectories of propagation paths to be mapped and, as a result, the angular power distribution of received signals. A multi-elliptical propagation model (MPM) is used and compared with simulation results obtained for a statistical channel model developed by the 3rd Generation Partnership Project (3GPP). Transmission characteristics of propagation environments such as power delay profile and antenna beam patterns define the geometric structure of the MPM. These characteristics were adopted based on the 3GPP standard. The obtained results show the possibility of using the presented novel MPM-based approach to model the required minimum separation angle between co-channel beams under line-of-sight (LOS) and non-LOS conditions, which allows mMIMO performance in 5G cells to be assessed. This statement is justified because for 80% of simulated samples of intra-cell signal-to-interference ratio (SIR), the difference between results obtained by the MPM and commonly used 3GPP channel model was within 2 dB or less for LOS conditions. Additionally, the MPM only needs a single instance of simulation, whereas the 3GPP channel model requires a time-consuming and computational power-consuming Monte Carlo simulation method. Simulation results of intra-cell SIR obtained this way by the MPM approach can be the basis for spectral efficiency maximization in mMIMO cells in 5G systems.

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