scholarly journals Performance Comparison of Modulation Schemes and Adaptive Modulation Scheme with CQI Feedback

Author(s):  
Pratik Matkar ◽  
Prasham Jain
2012 ◽  
Vol 468-471 ◽  
pp. 2603-2606
Author(s):  
Shi Bin Su ◽  
Yuan Yuan Gao ◽  
Ya Jun Zhang ◽  
Bao Feng Yang ◽  
Ya Long Zhang

In this paper, two different modulation schemes are developed in multiple access relay cooperation with network coding. Performance analysis and simulation results show that there is one point where the two modulation schemes have the same system outage probability. This finding can be utilized to propose an adaptive modulation scheme.


Author(s):  
NAZMIA KURNIAWATI ◽  
YULI KURNIA NINGSIH ◽  
SOFIA DEBI PUSPA ◽  
TRI SWASONO ADI

ABSTRAKKomunikasi Vehicle to Infrastructure (V2I) memungkinkan kendaraan dapat terhubung ke berbagai macam infrastruktur. Dengan kondisi kendaraan yang bergerak, maka kondisi lingkungan yang dilewati mempengaruhi parameter komunikasi. Implementasi modulasi adaptif pada skema V2I memperbolehkan sistem menggunakan skema modulasi yang berbeda untuk mengakomodasi perubahan kondisi lingkungan. Pada penelitian ini digunakan skema modulasi QPSK, 8PSK, dan 16-QAM dengan memanfaatkan reinforcement learning dan algoritma epsilon greedy untuk menentukan skema modulasi yang digunakan berdasarkan level AWGN. Dari hasil simulasi dengan kondisi nilai epsilon yang divariasikan dari 0.1 hingga 0.5 didapatkan bahwa semakin tinggi nilai epsilon maka semakin sering agen tidak memilih skema modulasi dengan reward tertinggi.Kata kunci: Reinforcement learning, Modulasi Adaptif, AWGN ABSTRACTVehicle to Infrastructure (V2I) communication allows vehicles to be connected to various infrastructures. Under the scenario of a moving vehicle, the environmental conditions which is passed by the vehicle will affect the communication parameters. The adaptive modulation implementation in the V2I scheme allows the system to use different modulation schemes to accommodate changing environmental conditions. In this study, the QPSK, 8PSK, and 16-QAM modulation schemes were used by utilizing reinforcement learning and the epsilon greedy algorithm to determine the modulation scheme used based on AWGN level. From the simulation results with the conditions of the epsilon value varying from 0.1 to 0.5, it is found that the higher the epsilon value, the more often the agent does not choose the modulation scheme with the highest reward.Keywords: Reinforcement learning, Adaptive Modulation, AWGN


Author(s):  
SABITA NAHATA ◽  
SUBRATA BHATTACHARYA

Inter-symbol interference (ISI) due to multipath fading is a vital problem in high-speed wireless communication which restricts communication quality and capacity. Therefore, in addition to choosing a fading mitigation technique, it is also important to strategically select a modulation scheme for effective data transmission. Recent literature review on wireless standards, such as 3G and 4G indicates that QAM and QPSK are suitable choices for data transmission. In this paper, a comparative analysis on selected modulation schemes is performed in a fading environment. The mitigation of fading is done using adaptive equalization technique. Also, we show that the signal to noise ratio (SNR) is an important parameter to choose. It is observed that, even when an adaptive equalizer is used at the receiver, a very low SNR gives very high symbol error rate (SER). We derive some important conclusions from our simulation result: QPSK shows minimum SER, whereas 256-PSK and 256-PAM perform worse. Given its spectral efficiency and a low SER, the best choice is 256- QAM.


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.


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