Time-Frequency Training OFDM with High Spectral Efficiency and Reliable Performance in High Speed Environments

2012 ◽  
Vol 30 (4) ◽  
pp. 695-707 ◽  
Author(s):  
Linglong Dai ◽  
Zhaocheng Wang ◽  
Zhixing Yang
2013 ◽  
Vol 765-767 ◽  
pp. 2801-2804
Author(s):  
Ya Jing Wang ◽  
Ya Zhen Li ◽  
Li Qun Huang

The fourth generation mobile communication system is a high-speed broadband wireless communication system, it needs MIMO and OFDM technology which have high spectral efficiency and suitable for a multi-path fading channel. Because the MIMO-OFDM system is still an multi-carrier modulation system, the main drawback is the high PAPR value. This paper proposed an improved algorithm based on optimized PTS to reduce PAPR in STBC MIMO-OFDM system. The simulation results show that the improved algorithm can effectively reduce the PAPR value and do not increase the amount of computation in STBC MIMO-OFDM system.


Author(s):  
KAMALA KANNAN P ◽  
GURU VIGNESH B ◽  
INIYAN P A ◽  
ILAVARASAN T

Orthogonal Frequency Division Multiplexing (OFDM) is a modulation technique which is now used in most new and emerging broadband wired and wireless communication systems such as standard 802.11a/b/g/n, Digital Video Broad casting Television (DVB-TV), and Long Term Evolution (LTE) in the next mobile generation, due to its capacity in solving the problems of Inter-Symbol Interference (ISI) caused by the effects of the dispersive channel. Very recently researches focus on applying OFDM technology in optical fiber communication systems. Optical OFDM is well suited for high speed transmission systems with high spectral efficiency and attracted significant attention from the optical communication community. One of the major issues that degrade the performance of optical OFDM networks is its fiber non-linearity. Fiber non-linearities represent the fundamental limiting mechanisms to the amount of data that can be transmitted on a single optical fiber. Non-linear effects arise as optical fiber data rates, transmission lengths, number of wavelengths, and optical power level increases. Therefore, the effect of non-linearity in high data rate optical networks needs to be controlled to enhance link performances. In this paper, a nonlinearity compensation technique (Hermitian Symmetry) is implemented to improve the performance of OFDM based optical networks. This would provide high spectral efficiency, low ISI and very good Bit Error Rate (BER) performances without increasing the complexity of the network. The optical OFDM transmission system with fiber non-linearity compensation is simulated using Virtual Photonics Integrated (VPI) software.


Author(s):  
Usman Illahi ◽  
Javed Iqbal ◽  
Muhammad Ismail Sulaiman ◽  
Muhammad Alam ◽  
Mazliham Mohd Su'ud

<p>A novel technique of multiplexing called Tributary Mapping Multiplexing (TMM) is<br />applied to a single channel wavelength division multiplexing system and performance is monitored on the basis of simulation results. To elaborate the performance of TMM in this paper, a 4-User TMM system over single wavelength channel is demonstrated. TMM showed significant tolerance against narrow optical filtering as compared to that of conventional TDM at the rate of 40 Gbit/s. The above calculations are made by optical filter bandwidth and dispersion tolerance that was allowed at minimum. The spectral efficiency achieved by this TMM was 1 b/s/Hz and it was executed by using transmitters and receivers of 10 Gbit/s without polarized multiplexing. The high spectral efficiency, high dispersion tolerance and tolerance against strong optical filtering makes TMM an efficient technique for High<br />Speed Fiber Optic Communication.</p>


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