Suitability of Coded Orthogonal Frequency Division Multiplexing (COFDM) for Multimedia Data Transmission in Wireless Telemedicine Applications

2007 ◽  
Author(s):  
K. Thenmozhi ◽  
V. Prithiviraj
Keyword(s):  
Data Transmission ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multimedia Data ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Multimedia Data Transmission

scholarly journals A REVIEW OF NOVEL APPROACH FOR REDUCTION IN SUB CARRIER PEAK TO AVERAGE POWER RATIO IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING

2020 ◽  
Vol 5 (2) ◽  
pp. 114-122
Author(s):  
Manju Sangar ◽  
Professor Brijendra Mishra ◽  
Professor Bhupendra Verma
Keyword(s):  
High Power ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
High Mobility ◽  
Low Complexity ◽  
Multimedia Data ◽  
Papr Reduction ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division

In last few decades the demand for multimedia data services has grown up fastly. One of the most promising multicarrier system, Orthogonal Frequency Division Multiplexing (OFDM) allow large number of capacity the number of subcarriers, high data rates and ubiquitous coverage with high mobility. But OFDM is extensively affected by peak to average power ratio (PAPR). Unfortunately, the high PAPR inherent to OFDM signal envelopes will frequently drive high power amplifiers (HPAs) which are operate in the nonlinear region. The nonlinearity of the High Power Amplifier exhibits phase and amplitude distortions, which causes loss of orthogonality between the subcarriers; also (ICI) is introduced in the source signal. This dissertation is basically focused on PAPR reduction in OFDM system and measuring BER in different Modulation Technique. In PAPR reduction Signal companding methods have low complication, high distortion and spectral properties; however, we have limited PAPR reduction capabilities. Partial transmit sequences (PTS) and selected mapping (SLM), have also been considered for PAPR reduction. Such kind of techniques are very efficient and distortion less, Also the SLM is very good technique to the PAPR problem in single carrier system. This method has low complexity as well as it is data independent. In this paper, we are describing a combine technique of SLM and PTS to minimize the PAPR. In PTS scheme, number of sub blocks increases; the IFFT block to be performed for sub blocks also increases. Simulation results have shown that the reductions of PAPR of proposed scheme is more than PTS and SLM methods as well as the difficulty reduced considerably.

The Study of Navigation Light Cable Communication Based on OFDM

2011 ◽  
Vol 422 ◽  
pp. 218-223
Author(s):  
Xiu Yan Wang ◽  
Jin Lin Wang ◽  
Jia Quan Lin ◽  
Zong Shuai Li
Keyword(s):  
Real Time ◽  
Monitoring System ◽  
Data Transmission ◽  
Orthogonal Frequency Division Multiplexing ◽  
Working Condition ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
The Real ◽  
Cable Channel ◽  
Cable Communication

Navigation light monitoring system is designed to detect the working condition of each light with circuit cable carrier. However, the real-time detecting information could be inaccurate as a result of the existence of disturbances such as noise, multi-path effect and channel decline, when the data transmission happens in light cable as the channel. In this paper, OFDM (Orthogonal Frequency Division Multiplexing) is presented to be used in circuit cable communication. And the reason and capability of the resistance to these disturbances in OFDM are analyzed. Finally, the result is concluded that OFDM used in navigation light cable channel is feasible.

scholarly journals Research on a Unified Framework Based on Linear Frequency Modulation and Orthogonal Frequency-Division Multiplexing

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Tianhong Zhang ◽  
Limei Xu ◽  
Kaiyu Qin ◽  
Xiao Yan
Keyword(s):  
Remote Control ◽  
Frequency Modulation ◽  
Data Transmission ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Unified Framework ◽  
Control Data ◽  
Target Speed ◽  
Signal Features

This paper proposes a unified system framework based on linear frequency modulation (LFM) and orthogonal frequency-division multiplexing (OFDM) as a solution for resource sharing, especially sharing space and hardware. The proposed OFDM-LFM framework can not only transmit data flow by OFDM but also make it possible to extract features from the signal by LFM. Further, the signal features are used to construct a pseudospectrum related to the target speed and distance, thereby estimating the speed and distance of the target. Unified means using signal features to estimate target speed and distance while ensuring data transmission including communication and remote control data information. Besides the traditional data transmission mode, the ability of estimating target speed and distance is an additional benefit. The proposed unified framework makes control of transmission easier and saves more hardware resources. The simulation results show that the proposed LFM-OFDM framework can not only transmit data information including communication and remote control data information, but also estimate the speed and distance of the target by its signal features.

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