Effect of channel quality estimation error on the performance of interactive mobile video system using adaptive modulation scheme

2002 ◽  
Author(s):  
Fuyu Long ◽  
Kwok-Tung Lo ◽  
Wan-Chi Siu ◽  
Fuhui Long
2013 ◽  
Vol 427-429 ◽  
pp. 2558-2561
Author(s):  
Guo Quan Li ◽  
Ke Tang ◽  
Jin Zhao Lin ◽  
Yu Pang ◽  
Zhang Yong Li ◽  
...  

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.


Author(s):  
Sajal Saha ◽  
Angana Chakraborty ◽  
Asish K. Mukhopadhyay ◽  
Anup Kumar Bhattacharjee

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.


Author(s):  
D. Tjondronegoro

Sports video is very popular thanks to its in-progress (live) information and entertainment values. Many users are motivated to access sports video using mobile devices, since they often cannot watch the game on their sofa due to a busy life and inability to cope with lengthy games. The current generation of mobile video services has only focused on supporting the when and where consumers can watch their favorite sports matches. Since total control over playback and content is neglected, users often have to settle with low-quality videos and static content, which have been pre-processed. This limitation slows down the progress towards an era in which users are comfortable using their mobile devices to enjoy sports broadcasts while gaining total control over what they can watch at their most convenient time and place. In this article, we will describe a mobile video system which offers users full support over the when, where and how they want to watch sports video. The main new features offered are: (1) non-linear navigation within single and/or multiple documents; (2) customizable and personalized summaries; (3) multimodal access and video representation.


2013 ◽  
Vol 791-793 ◽  
pp. 1941-1944
Author(s):  
Ya Dan Zheng ◽  
Ming Ke Dong ◽  
Jian Jun Wu

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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