Measurements for performance degradation of adaptive modulation scheme caused by channel quality estimation error

2003 ◽  
Vol 150 (2) ◽  
pp. 80 ◽  
Author(s):  
F.Y. Long ◽  
K.T. Lo
Keyword(s):  
Estimation Error ◽  
Adaptive Modulation ◽  
Performance Degradation ◽  
Modulation Scheme ◽  
Quality Estimation ◽  
Channel Quality

Exploration of Modulation and Demodulation for Body Area Networks

2013 ◽  
Vol 427-429 ◽  
pp. 2558-2561
Author(s):  
Guo Quan Li ◽  
Ke Tang ◽  
Jin Zhao Lin ◽  
Yu Pang ◽  
Zhang Yong Li ◽  
...  
Keyword(s):  
Adaptive Modulation ◽  
Algorithm Design ◽  
Modulation Scheme ◽  
Body Area ◽  
Modulation And Demodulation ◽  
Channel Quality ◽  
Awgn Channel ◽  
Simulation Results ◽  
And Performance ◽  
Ber Performance

Modulation and demodulation are two important parts in BAN baseband transmission systems. Different demodulation algorithms may affect the BER performance of the entire system seriously. Referring to IEEE 802.15.6 BAN standard, theoretical analysis and algorithm design of the modulation and demodulation for π/2-DBPSK and π/4-DQPSK is carried out and simulation results of BER performance are presented in this paper. In AWGN channel, both modulations achieve good performance, and performance degradation of π/4-DQPSK happens in multipath channel which may not satisfy the requirements. Adaptive modulation is considered to solve this problem by choosing different modulation scheme according to channel quality.

WiMAX and Wi-Fi Services through Mobile Networks

2016 ◽  
pp. 160-189
Author(s):  
Sajal Saha ◽  
Angana Chakraborty ◽  
Asish K. Mukhopadhyay ◽  
Anup Kumar Bhattacharjee
Keyword(s):  
Mobile Networks ◽  
Antenna Selection ◽  
Adaptive Modulation ◽  
Path Loss ◽  
Mobile Wimax ◽  
Modulation Scheme ◽  
Coding Schemes ◽  
Radio Resources ◽  
Integrated Architecture ◽  
Restricted Mobility

WIFI and WiMAX became popular worldwide due to simplicity of installation and cost reduction compared with traditional DSL cable. The key challenge of WiFi is the restricted mobility of the user whereas mobile WiMAX (IEEE 802.16m) provides ubiquitous environment to the user. The recent challenges of WiMAX is managing radio resources (both licensed and unlicensed) efficiently through different QoS service classes, implementing proper modulation and coding schemes at PHY, proper antenna selection in MIMO to achieve better QOS. User can avail the benefits of speed and mobility through an integrated architecture comprising WiFi and WiMAX. This chapter provides an in depth performance evaluation of Mobile WiMAX and WiFi under various Modulation and Coding Schemes (MCS), cyclic prefixes and different path-loss models under integrated environment. Moreover, we present an optimized adaptive modulation scheme that senses the SNR and adaptively switches to required MCS to achieve desired level of QoS and link stability.

Channel Quality Approximation Based on Shadow Fading Model in GEO Mobile Satellite System

2013 ◽  
Vol 791-793 ◽  
pp. 1941-1944
Author(s):  
Ya Dan Zheng ◽  
Ming Ke Dong ◽  
Jian Jun Wu
Keyword(s):  
Large Scale ◽  
Adaptive Modulation ◽  
Original Data ◽  
Satellite System ◽  
Adaptive Modulation And Coding ◽  
Small Scale ◽  
Shadow Fading ◽  
Channel Quality ◽  
The Difference ◽  
Mobile Satellite

CQI(Channel Quality Indicator) is an essential indicator for AMC(Adaptive Modulation and Coding) technique in LTE. Due to the long delay of GEO satellite channel, CQI prediction is necessary to ensure effective AMC. This paper proposes the approximation from real CQI data containing small scale fading to that containing only large scale fading to do prediction. The concrete correlation features and the difference between the approximation and the original data are all analyzed. Simulation is done for confirmation. It shows that the approximate large scale CQI data is feasible and rational for prediction and ensuring AMC efficiency.

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