Optimal Performance of OFDM Signal using PAPR Reduction Techniques in LTE Systems (original) (raw)
Related papers
Performance Analysis of PAPR Reduction Using DFT-Spreading OFDMA Technique
The 3GPP long term evolution (3GPP-LTE) has adopted the Discrete Fourier Transform Spreading Orthogonal Frequency Division Multiple Access (DFTS-OFDMA) technique to be used in the uplink air interface for the next generation cellular systems. The DFTS-OFDMA is also a candidate of radio interface technologies for the IMT-Advanced standards in ITU-R. This technique has been adopted for uplink transmission due to its attractive feature of lower PAPR archived by precoding data symbols using a DFT operation at the transmitter. In this paper, we analyse the performance of DFT-Spreading OFDMA technique in PAPR reduction by using the IFDMA and LFDMA subcarriers mapping modes. We also analyse the performance of the DFTS OFDMA technique for PAPR reduction as the number of subcarriers allocated to each user varies, specifically with the LFDMA subcarriers mapping mode. Simulation results show that, the IFDMA improves PAPR performance significantly than LFDMA with pulse shaping and wihout pulse ...
Performance Improvement of Papr Reduction For OFDM Signal in LTE System
International Journal of Wireless & Mobile Networks, 2013
Orthogonal frequency division multiplexing (OFDM) is an emerging research field of wireless communication. It is one of the most proficient multi-carrier transmission techniques widely used today as broadband wired & wireless applications having several attributes such as provides greater immunity to multipath fading & impulse noise, eliminating inter symbol interference (ISI), inter carrier interference (ICI) & the need for equalizers. OFDM signals have a general problem of high peak to average power ratio (PAPR) which is defined as the ratio of the peak power to the average power of the OFDM signal. The drawback of high PAPR is that the dynamic range of the power amplifier (PA) and digital-to-analog converter (DAC). In this paper, an improved scheme of amplitude clipping & filtering method is proposed and implemented which shows the significant improvement in case of PAPR reduction while increasing slight BER compare to an existing method. Also, the comparative studies of different parameters will be covered.
Performance Comparison of OFDMA and SCFDMA in LTE Systems
2014
Single carrier frequency division multiple access (SCFDMA) is adopted for the uplink transmission of Long Term Evolution (LTE). SCFDMA is modified form of OFDMA which uses discrete Fourier transform (DFT) spreading before OFDMA modulation. LTE uses SCFDMA scheme for the uplink transmissions due to its lower peak to average power ratio (PAPR) and orthogonal frequency division multiplexing access (OFDMA) in downlink. In this paper we analyze PAPR using pulse shaping and without pulse shaping filters. Simulation results show that SCFDMA has lower PAPR than OFDMA. SCFDMA has 10 dB PAPR improvement than standard OFDMA without using pulse shaping filter .With pulsed shaping filter PAPR of SCFDMA is improved by 7db than standard OFDMA.
PAPR Reduction for Improved Efficiency of OFDM Modulation for Next Generation Communication Systems
International Journal of Electrical and Computer Engineering (IJECE)
Highly linear power amplifiers are required for transferring large amount of data for future communication. Orthogonal frequency division multiplexing (OFDM) provides high data rate transmission capability with robustness to radio channel impairments. It has been widely accepted for future communication for different services. But, it suffers from high value of peakto-average power ratio (PAPR). High value of PAPR drives high power amplifiers in saturation and causes it to operate in the nonlinear region. In this paper, comparative study of four different PAPR reduction techniques: clipping and filtering (CF), selective mapping method (SLM), partial transmit sequence (PTS) and DFT-spread technique have been done. Mathematical modeling and Matlab simulations have been performed to arrive at the results with 4 QAM modulation format and 1024 number of sub carriers. At 0.01 % of complementary cumulative distribution function (CCDF) significant reduction of 11.3, 3.5, 3.4 and 1.0 dB have been obtained with DFT-spread, SLM, PTS and CF techniques respectively.
Analysis of PAPR Reduction Schemes in LTE-OFDM System
Orthogonal Frequency Division Multiplexing (OFDM) is one of the most promising technique for today’s wireless broadband communication systems.3GPP’s LTE was the first to adopt OFDM as its downlink technique. One of the major disadvantage is its high peak-to- average power ratio (PAPR). In this paper two main PAPR Reduction Techniques i.e. Selective Mapping (SLM) and Partial Transmit Sequence (PTS) are discussed along with their advantages, disadvantages and comparison between them.
A COMPARATIVE ANALYSIS OF PAPR OF SC-FDMA AND OFDMA FOR LTE SYSTEMS
Long Term Evolution is a new advancement in the era of cellular technology emerged in recent decade that can accommodate the features of quite efficient radio access with high peak data rates as well as high capacity for voice links. Actually it is a journey toward 4 th generation with the recent 2G and 3G network operators. This revolution is an improvement over GSM, EDGE G, WCDMA/UMTS, and HSPDA and then HSPA+ to fulfil the demand of high speed mobile networks. This paper primarily describes a comparison of Single Carrier Frequency Division Multiple Access (SC-FDMA) and Orthogonal Frequency Division Multiple Access (OFDMA) multiple access techniques.This comparison is carried out for the selection of multiple access schemes for the implementation of Long Term Evolution (LTE) systems. Also the advantages and disadvantages of SC-FDMA and OFDMA schemes are described. SC-FDMA is proved better than OFDMA in terms of Peak to average power ratio (PAPR).SCFDMA and OFDMA systems are modelled with MATLAB for PAPR analysis.
A novel algorithm for PAPR reduction in LTE system
Proceedings of the International Conference on Advances in Computing, Communications and Informatics - ICACCI '12, 2012
High Peak to Average Power Ratio (PAPR) is still one of the most important challenges in Orthogonal Frequency Division Multiplexing (OFDM) system. In this paper, we proposed a hybrid algorithm that is based selected mapping (SLM) technique for PAPR reduction in OFDM system. This algorithm incorporates the transformations into the SLM technique. Rather than using only Discrete Fourier Transform (DFT) in the traditional SLM technique, we propose to use Discrete Cosine Transform (DCT) and Discrete Sine Transform (DST) as well as DFT in the selection process, to get the lowest PAPR. The simulation results, based on simplified long term evaluation (LTE) system, show that the proposal technique can reduce the PAPR to about 3.2dB compared to traditional OFDM for N=512 at clipping probability of 10 with low additive complexity.
LTE Quality of Service Enhancement Under OFDM Modulation Techniques
Wireless Personal Communications, 2020
Recently, to satisfy the ever-growing data needs, Long Term Evolution (LTE) has been deployed by many operators. LTE enables better spectrum management and avoids the adjacent channel interference by using the Orthogonal Frequency Division Multiple Access (OFDMA) for downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) for uplink connection. Even though the spectrum is limited, the number of active devices is increasing which requires the need for extra spectrum. OFDM is capable of better Quality of Service (QoS) as it avoids the multipath fading using equalization and immune to inter-symbol interference, in addition to its attractive spectral efficiency. However, the LTE system is suffered from Peak to Average Power Ratio (PAPR) which reduces the QoS of the communication. Therefore, in this paper, we have proposed a QoS enhancement using a hybridized clipping-selective mapping (Clip-SLM) technique. Different QoS enhancement methods are evaluated for different modulation techniques, phase sequences, and number of sub-carriers. From the simulation results, we have shown that the proposed hybridized technique results in significant PAPR reduction which results in substantial Bit Error Rate (BER) reduction and hence QoS enhancement.
PAPR Reduction in DFT- Spread OFDMA using Companding Transform
IJSRD, 2014
Orthogonal Frequency Division Multiplexing (OFDM) is an efficient transmission technique for high data rate communication systems. The major problem of OFDM system is Peak to Average Power Ratio (PAPR) which reduces the efficiency of the system and increases the system complexity. In this paper, the two different techniques are combined together, so as to give the effective reduction in PAPR for OFDM, namely, DFT spreading and Two Piece-wise Companding (TPWC). DFT spread OFDM (DFTS-OFDM) has been selected as the uplink transmission scheme for long-term 3G evolution (LTE) and TPWC transform can provide significant PAPR reduction with low computational complexity, which is similar to other existing linear transforms. TPWC is proposed so as to compress large signal amplitudes and expand small ones with two different linear functions.
International journal of Computer Networks & Communications, 2014
One of the most important multi-carrier transmission techniques used in the latest wireless communication arena is known as Orthogonal Frequency Division Multiplexing (OFDM). It has several characteristics such as providing greater immunity to multipath fading & impulse noise, eliminating Inter Symbol Interference (ISI) & Inter Carrier Interference (ICI) using a guard interval known as Cyclic Prefix (CP). A regular difficulty of OFDM signal is high peak to average power ratio (PAPR) which is defined as the ratio of the peak power to the average power of OFDM Signal. An improved design of amplitude clipping & filtering technique of us previously reduced significant amount of PAPR with slightly increase bit error rate (BER) compare to an existing method in case of Quadrature Phase Shift Keying (QPSK) & Quadrature Amplitude Modulation (QAM). This paper investigates a comparative performance analysis of the different higher order modulation techniques on that design.