1. UNIVERSITY MALAYSIA PERLIS
SCHOOL OF COMPUTER AND COMMUNICATION ENGINEERING
Reduction Of PAPR In OFDM System
Based On Hybrid Techniques
Introduction:
Orthogonal Frequency Division Multiplexing (OFDM) is an attractive technique for high-bit-rate communication systems. It has been widely used in modern wireless communication because of its high data rate, immunity to delay spread, high frequency spectral efficiency and other advantages. Besides these advantages, one of the major drawback of OFDM is the high Peak-to-Average-Power Ratio (PAPR) of the Transmitter's output signal, that restricts/limits the system performance. OFDM is an enhanced modulation scheme, which can provide high data rate stream that can achieves: To degrade the effect of multipath phenomena associated with signals transferred in free space or in undersea media (Transmitted/Received); in which many researches/researchers do their best to handle the most trusted as possible to get the grantee results for the intended proposals.
INVENTOR:
Mr. Dheyauldeen Najm Abdulameer
Prof. Dr. R. Badlishah Ahmad
Dr. Ali A. Ahmed
Mr. Younis H. Kareem
CONTACT DETAIL:
Pusat Pengajian Kejuruteraan Komputer dan Perhubungan (PPKKP) Kompleks Pusat Pengajian Kejuruteraan Pembuatan Universiti Malaysia Perlis (UniMAP) Tingkat 1, Kampus Tetap Pauh Putra Arau, Perlis.
Problem Statement:
OFDM systems mainly suffers with the high value of the peak-to-average power ratio (PAPR) in signal transmission. The reduced value of this PAPR in turn increases the system efficiency which in turn decreases the radio frequency power amplifier price.
The work in this presentation aims to reduce the PAPR at less computation by using the Hybrid techniques. The method proposed here is the partial transmit sequence (PTS) and also various PTS sub blocks swapping creates the new OFDM signal.
The complexity reduction of partial transmit sequence (PTS) PAPR reduction scheme in OFDM systems by reducing the complexity of the IFFT architecture are investigated in this scheme. In the IFFT architecture of PTS OFDM scheme, there are a lot of additions and multiplications with zero, which are obviously unnecessary.
The complexity reduction of partial transmit sequence (PTS) PAPR reduction scheme in OFDM systems by reducing the complexity of the IFFT architecture are investigated in this scheme. In the IFFT architecture of PTS OFDM scheme, there are a lot of additions and multiplications.
System Advantages:
Reduce PAPR with the equivalent number of IFFT at reduced computation.
The samples from the generated signal are grouped in blocks.
Each symbol is modulated using the M-QAM or M-PSK method.
Forming the frequency domain OFDM frames.
Fig 1: Proposed Hybrid-Clipping Transmitter Scheme
Novelty :
A novel channel prediction scheme has been developed. The technique produces a new method for channel prediction.
The benefits of using Hybrid techniques in OFDM transmitter for reduction of PAPR.
Commercialize:
The popular use of the technology is for powering contactless smartcards, and system exists to power and recharge laptops and mobile devices.
In communication electronics device, powering the DVB-DAB implantable organ in house.
Wireless-satellite system for uplink/downlink vehicles
Fig 2: Modeling flow Matlab form in
Implementation Hybrid-OFDM (HYM) system
Block Diagram
QAM
M=16
Data size =128 Bit
QPSK
M=8
Data size =128 Bit
Fig. 3: Comparison of clipping methods for FFT-OFDM and T-OFDM where M=16 QAM- with data size of 128 Bit
Fig.4: Comparison of clipping and filtering methods for FFT-OFDM and T-OFDM where M=4 QPSK with data size of 1024 Bit.
Fig 5 : Clipping methods for using hybrid, adjacent and PTS Clip.
of FFT OFDM & T-OFDM where M=16 QAM, data size =128 Bit.
Fig.7: CCDF for PAPR of OFDM compared with OFDM
when M=2, 4, 8, 16, 32, 64, 128, 256 and 512.
Fig 6 : Clipping methods for using hybrid, adjacent and PTS Clip.
of FFT OFDM & T-OFDM where M=4 QPSK, data size =128 Bit.