A New SLNR-Based Precoding for Multiuser MIMO Downlinks

2014 ◽  
Vol 644-650 ◽  
pp. 4066-4071
Author(s):  
Xin Min Li
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Base Station ◽  
Semidefinite Relaxation ◽  
Constraint Condition ◽  
Multiuser Mimo ◽  
Power Constraint ◽  
Transmit Power ◽  
Simulation Results

A new SLNR-based precoding is proposed for multiuser MIMO downlinks, which pursues the goal that minimizes total transmit power under each user’s SLNR constraint. The goal problems can be successfully solved by using semidefinite relaxation (SDR) techniques, and power constraint condition added in goal problems can efficiently reduce total transmit power of the base station. Simulation results show that our proposed scheme is almost feasible for users with one antenna, and it has better bit error rate (BER) and lower total transmit power than the maximal-SLNR based precoding method, when it satisfies large SLNR thretholds.

A Fast Adaptive Transmit Power and Bit Allocation in OFDM System

2013 ◽  
Vol 765-767 ◽  
pp. 444-447
Author(s):  
Juan Wen ◽  
Qi Ming Tian
Keyword(s):  
Theoretical Analysis ◽  
Bit Error Rate ◽  
Error Rate ◽  
Bit Allocation ◽  
Ofdm System ◽  
Transmit Power ◽  
Allocation Algorithm ◽  
Bisection Algorithm ◽  
Simulation Results ◽  
Adaptive Transmit Power

In this paper, we propose a fast and optimal adaptive transmit power and bit allocation algorithm, which is called Bisection Searching Level (BSL) for wireless OFDMA systems. The algorithm aims at maximization of data rate under the constraints of total transmit power and bit error rate (BER). BSL is based on water pouring approach, and adopt bisection algorithm to find the water pouring level under discrete bit restriction. Both theoretical analysis and simulation results demonstrate the optimality of our proposed algorithm.

Energy-Efficient Joint Power Allocation and Relay Selection in Bit Error Rate Constrained Two-Way Relay Network

2015 ◽  
Vol 7 (4) ◽  
pp. 1-14
Author(s):  
Rashi Mehrotra ◽  
Ranjan Bose
Keyword(s):  
Power Consumption ◽  
Power Allocation ◽  
Bit Error Rate ◽  
Error Rate ◽  
Energy Efficient ◽  
Relay Selection ◽  
Relay Network ◽  
Transmit Power ◽  
Selection Scheme ◽  
Simulation Results

In this paper, the authors have proposed energy efficient power allocation and relay selection scheme in a two-way amplify-and-forward (AF) relay under bit error rate (BER) constrained network. They have derived an expression for the overall BER for Rayleigh fading channel. Based on minimum power consumption in the network, the authors have addressed the problem of power allocation by converting geometric programming to a convex optimization problem. A closed form solution of power allocation is found, which aims at minimizing total transmit power for the overall BER constrained network. The authors have evaluated minimum total transmit power for two-way AF relay network. Based on minimum total transmit power, a novel relay selection scheme has been proposed. Simulation results demonstrate that the proposed two-way power allocation and relay selection scheme can significantly minimize power consumption under BER constrained network as compared to the existing relay transmission. The proposed power allocation scheme gives 3 dBW gain than one-way relay transmission. The proposed relay selection method also outperforms the random relay selection by 24 dBW. The simulation results are corroborated with the analytical result

scholarly journals A Study on the Effect of UWB Interference on Downlink UMTS System

2010 ◽  
Vol 6 (2) ◽  
pp. 107-110
Author(s):  
Maan Al-Adwany ◽  
Esra’a Najim ◽  
Ala’a Ali ◽  
Amina Younis
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Base Station ◽  
Universal Mobile Telecommunication System ◽  
Transmitted Power ◽  
Mobile Telecommunication ◽  
Telecommunication System ◽  
Minimum Requirements ◽  
Downlink System ◽  
Simulation Results

In this paper, we evaluate the performance of UMTS (Universal Mobile Telecommunication System) downlink system in vicinity of UWB system. The study is achieved via simulating a scenario of a building which is located within UMTS cell borders and utilizes from both UMTS and UWB appliances. The simulation results show that the UMTS system is considerably affected by the UWB interference. However, in order to battle this interference and achieve reasonable BER (Bit Error Rate) of 10-4, we found that it is very necessary to carefully raise the UMTS base station transmitted power against that of UWB interferer. So, the minimum requirements for UMTS system to overcome UWB interference are stated in this work.

Bit Error Rate Performance Analysis of Hybrid Subcarrier Intensity Modulation-Based FSO with Spatial Diversity in Various Weather Conditions

2019 ◽  
Vol 40 (3) ◽  
pp. 307-314 ◽  
Author(s):  
Rajat Kumar Giri ◽  
Bijayananda Patnaik
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Weather Conditions ◽  
Spatial Diversity ◽  
Intensity Modulation ◽  
Free Space Optical ◽  
Diversity Techniques ◽  
Link Distance ◽  
Simulation Results ◽  
Improved Performance

Abstract In this paper, we study the performance improvement of free space optical (FSO) communication system with spatial diversity techniques employing hybrid pulse position modulation-binary phase shift keying-subcarrier intensity modulation (PPM-BPSK-SIM). The involvement of multiple photo-detectors in diversity based FSO systems offers an effective way to overcome scntillation. In this paper, we have simulated the bit error rate (BER) with respect to different parameters like average SNR, link distance at various weather conditions. The simulation results are verified in Matlab environment with the mathematical analysis. The simulation results show that higher order single input multiple output (SIMO) system achieves better BER performance and hybrid PPM-BPSK-SIM has significant improved performance than the common modulation schemes like PPM, BPSK-SIM.

Rate-Compatible Punctured Ring Convolutional Coded Continuous Phase Modulation

2012 ◽  
Vol 195-196 ◽  
pp. 217-220
Author(s):  
Lei Zhang ◽  
Man Ping Tong ◽  
Hong Bo Wang
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Phase Modulation ◽  
Euclidean Distance ◽  
Convolutional Codes ◽  
Continuous Phase ◽  
Transmission Efficiency ◽  
Continuous Phase Modulation ◽  
Simulation Results ◽  
Squared Euclidean Distance

In this paper, continuous phase modulation (CPM) with rate-compatible punctured ring convolutional codes is investigated. Some typical schemes with maximum normalized minimum squared euclidean distance (NMSED) are searched and given. The performance of bit error rate for rate-compatible punctured ring convolutional coded CPM on AWGN channel is simulated, and simulation results show that this system can provide good performance of bit error rate and variable-rate capabilities. Furthermore, simulation results also prove that the transmission efficiency increases when code rate is decreasing.

A Novel Construction Method of QC-LDPC Codes Based on Generalized ACE Constrained

2013 ◽  
Vol 760-762 ◽  
pp. 1684-1689
Author(s):  
Hong Hao Zhao ◽  
Fan Bo Meng ◽  
Qing Qi Zhao ◽  
Jie Wang
Keyword(s):  
Computational Complexity ◽  
Bit Error Rate ◽  
Error Rate ◽  
Ldpc Codes ◽  
Excellent Performance ◽  
Frame Error Rate ◽  
Signal Noise ◽  
Extrinsic Message Degree ◽  
Lower Complexity ◽  
Simulation Results

Recently, structured LDPC codes have been focused on due to excellent performance and lower complexity. An improved construction of QC-LDPC based on a modified PEG algorithm is proposed in this paper. The modified Progressive Edge-Growth algorithm is a PEG algorithm with Approximated Cycle Extrinsic Message Degree (ACE) metric, which is used to describe the connectivity of cycles. The approach can maximize the girth of the cycles, improve the connectivity of cycles and have the advantages of QC algorithms. The simulation results demonstrate that the PEG algorithm based on ACE has lower Bit Error Rate (BER) and Frame Error Rate (FER) than the original PEG algorithm at the low Signal Noise Ratio (SNR) values, and has a relatively lower computational complexity.

Simulation Implementation and Analysis of the OFDM Modulated by MPSK and M-QAM

2014 ◽  
Vol 543-547 ◽  
pp. 2221-2224
Author(s):  
Li Ming Yang ◽  
Jia Guo ◽  
Hong Wei Ding ◽  
Yong Wang ◽  
Yi Fan Zhao
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Ofdm System ◽  
Channel Simulation ◽  
Rayleigh Channel ◽  
Simulation Results

Simulated for OFDM system modulated by 16PSK, 16QAM and 64QAM, and then we compared and analyzed their performance in the Rayleigh channel and 2 paths Rayleigh channel. Simulation results show that under the same conditions, Bit Error Rate (BER) of MQAM modulation system is lower than the same order MPSKs

Research on Four Water-Filling Power Distribution Schemes in MU-MIMO System

2014 ◽  
Vol 721 ◽  
pp. 635-638
Author(s):  
Yong Bo Zhang ◽  
Jian Xin Li ◽  
Wei Min Wen
Keyword(s):  
Channel Capacity ◽  
Bit Error Rate ◽  
Error Rate ◽  
Power Distribution ◽  
Mimo System ◽  
Base Station ◽  
Block Diagonalization ◽  
Total Transmission ◽  
Water Filling ◽  
Multiuser Scheduling

It is a key issue to distribute the total transmission power among different data streams leading to larger channel capacity or lower bit error rate at the base station in MU-MIMO system. Based on MU-MIMO system model applying block diagonalization precoding (BDP) this paper presented four kinds of water-filling power distribution schemes which had been simulated for random scheduling and multiuser scheduling. The simulation results showed that respective water-filling power distribution owned maximum channel capacity and united water-filling power distribution resulted in the lowest bit error rate (BER).

scholarly journals Performance Evaluation of Downlink WiMAX System in Vicinity of UWB System

2011 ◽  
Vol 7 (2) ◽  
pp. 120-124
Author(s):  
Maan Al-Adwany
Keyword(s):  
Performance Evaluation ◽  
Bit Error Rate ◽  
Error Rate ◽  
Office Building ◽  
Transmitted Power ◽  
Minimum Requirements ◽  
Downlink System ◽  
Simulation Results ◽  
Wimax System

In this paper, we evaluate the performance of WiMAX downlink system in vicinity of UWB system. The study is achieved via simulating a scenario of an office building which utilizes from both WiMAX and UWB appliances. From the simulation results, we found that WiMAX system is largely affected by the UWB interference. However, in order to overcome the interference problem and achieve reasonable BER (Bit Error Rate) of 10-4, we found that it is very necessary to raise the WiMAX transmitted power in relative to that of UWB interferer. So, the minimum requirements for WiMAX system to overcome UWB interference are stated here in this work.

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