PAPR Reduction Performance Research Articles

SLM based Circular (6, 2) mapping scheme with improved SER performance for PAPR reduction in OCDM without side information

Abstract Like OFDM, OCDM signal also suffers from high PAPR. SLM is an attractive PAPR reduction method but it needs to transmit the information regarding phase sequence i.e. SI to the receiver, which results in reduction in SE and data rate. Various SLM based SI free and SI embedding schemes are available in the literature. In this paper, different possible quaternary to 8-QAM mapping schemes for SI free SLM based PAPR reduction in OCDM system are discussed. Moreover, a new mapping scheme to eliminate the SI requirement has also been presented in this manuscript for SLM based PAPR reduction in OCDM system. Proposed Circular (6, 2) mapping scheme doesn’t require SI at the receiving end which results in increase in SE and data rate as compared to standard SLM technique. Random sequence with phase factors {1, −1} is used to generate the phase sequences for the proposed mapping scheme. Also, the analytical expression for SER of Circular (6, 2) mapping scheme over AWGN channel is derived. We have also evaluated the mathematical expression for SER of other possible quaternary to 8-QAM mapping schemes. Computer simulation using MATLAB are also carried out to investigate the performance of all these mapping schemes in terms of PAPR reduction performance as well as SER performance over AWGN and multipath Rayleigh fading channel. Proposed scheme achieves the same PAPR reduction and improved SER performance w.r.t. other six schemes taken into consideration.

An efficient SLM technique based on chaotic biogeography-based optimization algorithm for PAPR reduction in GFDM waveform

ABSTRACT High data rates, extremely low power consumption, and minimal end-to-end latency are considered to be mandatory requirements for 5G wireless networks. Rapid improvements in design and performance of 5G physical layer waveforms have become necessary. The drawback of Orthogonal Frequency Division Multiplexing (OFDM) is high PAPR, that causes signal distortion, which reduces system efficiency. Generalized frequency division multiplexing (GFDM) is a promising non-orthogonal multicarrier transmission scheme, which has recently received a great deal of attention towards future fifth generation (5G) wireless networks. It overcomes the limitations of orthogonal frequency division multiplexing (OFDM), while preserving most of the advantages of it. Selective Level mapping (SLM) is one of the PAPR reduction techniques, that uses the phase shift technology. In this paper, SLM based on Chaotic Biogeography Based Optimization (CBBO) algorithm is proposed to offer an efficient solution to the problem of high PAPR, existing in the GFDM waveforms. Experimental results prove that, the proposed CBBO–SLM technique provides significant improvement in terms of PAPR reduction, as compared to the conventional SLM methods, such as conventional GFDM and OFDM-SLM. The proposed novel scheme is most suitable for QAM and QPSK applications, as it provides good PAPR reduction performance, at lower computational complexity.

PAPR Reduction in MIMO-OFDM via Power Efficient Transmit Waveform Shaping

In this paper we revisit the long standing problem of peak-to-average power ratio minimization in MIMO-OFDM systems, with a new angle of approach on a well-known scheme. Utilizing the principles of tone reservation, we place dummy symbols, i.e., complex coefficients, on unused space-frequency resources with the aim to jointly minimize the transmit signal PAPR and the self-power consumption of the dummy symbols. This joint minimization is solved using three different proposed algorithms exhibiting varying degrees of computational complexity and PAPR reduction performance. Our proposed framework utilizes the strict PAPR expression, i.e., we take into account the average transmit power of the antenna, to simultaneously reduce the PAPR on all antennas while keeping the self-power consumption of the scheme minimal. Our simulation results show that this optimization objective provides better worst-case PAPR reduction and dummy symbol power consumption performance compared to the peak power minimization objective widely utilized in the tone reservation literature. Finally, we propose a novel take on a well-known block-diagonalization algorithm by exploiting knowledge on dummy symbol allocations, resulting in high-gain data streams in downlink transmission.

A novel cyclic delay combined with PSI to reduce PAPR of multi-IFoF signals in mobile fronthaul

In this paper, a novel scheme which utilizes cyclic delay combined with peak shrinking and interpolating (PSI), named as CD-PSI, is proposed to reduce the PAPR of multi-intermediate- frequency-over-fiber (Multi-IFoF) signals in mobile fronthaul. The key idea of the proposed scheme is to generate multi-IF OFDM signals through once combination of cyclic delay search so as to reduce the probability of the peak values. Then the PAPR is further reduced by peak shrinking and interpolating. The combination strategy can greatly reduce the sideband information overhead compared to PSI by reducing the recorded peak information. The simulation results demonstrate that the proposed scheme outperforms the previously proposed schemes in terms of both PAPR reduction performance and computational complexity.

PAPR reduction and error performance in MIMO-OFDM based wireless system: a comparative approach

PAPR reduction and error performance in MIMO-OFDM based wireless system: a comparative approach

PAPR reduction and error performance in MIMO-OFDM based wireless system: a comparative approach

PAPR reduction and error performance in MIMO-OFDM based wireless system: a comparative approach

PAPR reduction performance of bat algorithm in OFDM systems

The progression in technology requires improved modulation techniques for wideband digital communication systems. Orthogonal frequency division multiplexing is efficacious systems to fulfill high-speed data transmissions needs. However, high peak-to-average power ratio (PAPR) is one of the significant limitations on the performance and power efficiency of OFDM systems. Due to industrial and scientific relevance, the assessment of the PAPR reduction has become popular subject in the current decade. This study presents the combination of bat algorithm with partial transmit sequence scheme as an efficient PAPR reduction method with an alleviated computational load. A set of simulations with different partial transmit sequence schemes are performed to comparatively evaluate the PAPR reduction performance of the partial transmit sequence based on bat algorithm scheme in OFDM system. The simulation results elucidate that BA-PTS scheme can provides better PAPR reduction performance with less computational load.

Performance Analysis of MIMO-OFDM System Using SLM with Additive Mapping and U2 Phase Sequence for PAPR Reduction

Selective mapping (SLM) is one of the core techniques to mitigate the problem of high PAPR in the MIMO-OFDM system. But the complexity of inverse fast Fourier transform (IFFT) increases with increase in the number of phase sequence in the conventional SLM (C-SLM) scheme. However, we can generate alternate signal sequences along with the OFDM sequence without increasing the number of IFFT. This can be achieved by combining in both SLM with additive mapping (SLM-AM) and U2 phase sequence (SLM-U2) respectively. The computational complexity of both (SLM-AM) and (SLM-U2) is comparatively lesser than the C-SLM without degradation the BER and PAPR performance. But these schemes require some extra memory to save the alternative sequences. In this paper we derive a new low computational complexity equation for combination of both (SLM-AM) and (SLM-U2) schemes using M-QAM and M-PSK modulation in MIMO-OFDM system. In the proposed MIMO-OFDM model, we also analyze the computational complexity and PAPR reduction performance of various schemes like C-SLM, SLM-U2, SLM-AM and SLM-AM-U2 respectively. It has been observed that proposed (SLM-AM-U2) provides best PAPR reduction performance. Also, the computational complexity is least in this case.

Low complexity energy efficient orthogonal frequency division multiplexing communication system over underwater acoustic channel by partial transmit sequence peak to average power ratio reduction

We discourse the power consumption for underwater acoustic transceivers in this study. We have proposed a less computational complex underwater acoustic OFDM communication system. Underwater acoustic transceivers consume more power than that Radio frequency transceivers. The methods which are being utilized in Radio frequency cannot directly be applied to underwater acoustic system. Therefore, it needs to re-investigated and the new techniques should be introduced to achieve reliable and energy efficient acoustic data transmission. It also relies upon condition of acoustic channel and transmission distances. There is long-term battery-operated deployment of underwater acoustic modems in some applications. To maintain sustainable network operations an energy efficient OFDM system is required. In this paper, we have used partial transmit sequence peak to average power ratio reduction technique to design a novel energy efficient OFDM system for underwater acoustic channel with less complexity. This framework will be remarkably helpful in future for long term battery deployed applications of underwater acoustic transceivers. The results are expected to provide the enhanced performance of PAPR reduction with better sustainability. It has less complexity and better energy efficiency for underwater acoustic sensor/sensing networks.

A Novel Joint Scheme of PAPR Reduction and BER Performance Enhancement in Interleaved DCT-SCFDMA System

A Novel Joint Scheme of PAPR Reduction and BER Performance Enhancement in Interleaved DCT-SCFDMA System

A novel approach for reducing complexity in the SLM-GFDM system

The flexible nature of generalized frequency division multiplexing (GFDM) leads to superimposition of multiple subsymbols in time domain, the consequence of which is high PAPR. Selective mapping (SLM) is one of the prominent PAPR reduction techniques in GFDM, which uses bank of modulation matrices to generate a set of alternative signal representations. This procedure increases the complexity of the GFDM system enormously. In this paper, we utilize the concepts of conversion matrices and linearity to achieve low complexity with respect to the modulation matrices in the conventional SLM method. By using the proposed conversions we evolve at three modified SLM schemes which have much lower complexity. The first method uses the principle of linearity and two GFDM signals to generate the set of candidate signals while the second one uses only one GFDM signal along with conversion matrix. By adhering the advantages of two methods, the third method adds the concept of shifting matrix, which is an effective solution for tradeoff between PAPR performance and computational complexity. The obtained simulation results indicate that, when compared to conventional SLM scheme, the first proposed approach has inferior PAPR reduction performance, whereas, second and third proposed methods almost reach the performance of the conventional SLM scheme.

In brief

PAGE 888 A microring resonator suitable for sensing applications has been fabricated by researchers in Canada. They used femtosecond laser two-photon photopolymerization in SU-8 to create the microring resonator that is simpler in structure and configurability and has a high sensitivity, making it suitable for refractive index and temperature sensing in a range of industries. PAGE 903 Researchers in Taiwan have improved the performance of PAPR reduction of the General Precoding Scheme (GPC) without any increase of computational complexity, making it more compatible with the latest LTE and 5G NR standards. In their design, the current fixed performance of PAPR reduction in DFT-s-OFDM becomes adjustable to meet the needs of the various 5G services. A microring resonator forms a compact integrated component for sensing PAGE 864 Heart rate has been measured for the first time using radar echoes from a human head. Researchers in Japan developed a 79-GHz ultra-wideband 4 × 4 MIMO radar which could be used in unobtrusive devices for the long-term monitoring of newborn babies and the elderly, and could also be an alternative to wearable fitness trackers. PAPR reduction is improved in different GPC coding rates and channel bandwidths PAGE 897 Researchers in Korea have demonstrated Fermi-level depinning of Ge using N2 plasma treatment at room temperature. This nitridation process is compatible with CMOS and could become a key process to minimise the contact resistance of the metal/Ge interface, allowing high performance Ge-based CMOS devices to be realised. A mm-wave UWB array radar system measures heart rate from the head PAGE 892 A new unsupervised change detection method for SAR images has been proposed by researchers in China and the USA. Their method improves performance by reducing effects from outliers and noise, and also has a low computational complexity, making it more suitable for real-time practical applications such as city planning, natural disaster monitoring, and land cover analysis. Al contact to N2 plasma -treated n-type Ge shows good surface and interface uniformities. Change information is detected more effectively from SAR images using the new method

On the study of the relation between linear/nonlinear PAPR reduction and transmission performance for OFDM-based VLC systems.

The relation between the peak-to-average-power-ratio (PAPR) reduction schemes and the transmission performance of the orthogonal frequency division multiplexing (OFDM) based visible light communication (VLC) system is experimentally investigated. The linear selective mapping (SLM) scheme and the nonlinear logarithmic companding scheme are optimized by considering both PAPR reduction and bit error rate (BER) performance. It is demonstrated that the logarithmic companding scheme, albeit providing larger PAPR reduction when compared to the SLM scheme, may result in worse BER performance due to the additional noise induced in its expanding process. Both numerical and experimental investigations show that, at the expense of increased complexity and reduced efficiency, the VLC system using the linear SLM scheme exhibits better BER performance compared to the system using the nonlinear logarithmic companding scheme. We show that for a 400-Mb/s transmission at a distance of 1 m, the BER can be reduced from 2.02 × 10-3 to 2.51 × 10-4 by using logarithmic companding scheme. By using the linear SLM scheme, the BER can be further reduced to 1.77 × 10-6.

Research on modified selected mapping technique for PAPR reduction and reception performance improvement in 8QAM-OFDM optical access systems

BackgroundOrthogonal frequency division multiplexing has been regarded as one of the promising technologies for the optical access systems application. However, high peak-to-average power ratio will cause the signal distortion and enable the used amplifier to operate in nonlinear section.MethodsIn this paper, a modified selected mapping technique is introduced for reducing the peak-to-average power ratio and enhancing reception performance of the downstream 8QAM-OFDM signals in optical access systems.ResultsCompared with the traditional selected mapping technique, the PAPR value of 8QAM-OFDM optical downstream signals with 128 subcarriers is reduced by almost 2 dB using modified SLM when the complementary cumulative distribution function probability value is 10−2. Moreover, the bit error rate performance will be improved, while 10Gbit/s 8QAM-OFDM optical downlink signals are transmitted over single mode fiber with different access length.ConclusionsHence, the proposed scheme becomes more efficient for the future optical orthogonal frequency division multiplexing access systems.

Improved TKM-TR methods for PAPR reduction of DCO-OFDM visible light communications

The dc-biased optical orthogonal frequency division multiplexing (DCO-OFDM) system is experimentally demonstrated as an appealing candidate in future visible light communication (VLC) system. However, the intrinsic high PAPR drawback that the DCO-OFDM system suffers from still needs to be addressed and few effective approach has been found so far. To deal with this problem, in this paper, the tone reservation (TR) technique based the time domain kernel matrix (TKM-TR) schemes for reducing the PAPR are studied and applied to DCO-OFDM system. Aiming at the drawback of its severe tailing in previous TKM-TR schemes, first an improved TKM-TR scheme is proposed, in which the peak regrowth caused by severe tailing is eliminated by optimizing the scaling factors. In addition, considering the clipping ratio (CR) value in TKM-TR scheme is greatly related to the PAPR reduction performance, an extensively used heuristic global optimization algorithm, the particle swarm optimization (PSO) method is employed in TKM-TR to obtain a better CR for more PAPR reduction. Simulation results show that the improved TKM-TR scheme can efficiently address the tailing problem in previous TKM-TR schemes and achieve better PAPR reduction. Moreover, due to the powerful searching ability, PSO based TKM-TR scheme achieves more PAPR reduction and lower bit error rate (BER).

Performance analysis of OFDM receiver with modified PTS technique

Modified partial transmit sequence PTS technique with adjacent partitioning and four phase factors is implemented to enhance the PAPR performance of OFDM system and its PAPR reduction performance is evaluated in terms of the complementary cumulative distribution function CCDF. A multipath fading environment is considered and the performance of the OFDM receiver is evaluated using least square LS and minimum mean square error MMSE channel estimation methods. The performance of the receiver is evaluated in terms of mean square error MSE and bit error rate BER. The performance of the OFDM receiver is enhanced with PAPR reduction.

Modified PTS-based PAPR reduction for ACO-OFDM in visible light communications

In this letter, we propose a modified PTS-based PAPR reduction scheme for ACO-OFDM in VLC systems by exploiting the unoccupied subcarriers to transmit side information. A novel transmitter is presented to apply the PTS technique in ACO-OFDM VLC system without data throughput loss and an original power allocation method is also proposed to mitigate the power efficiency loss induced by the side information signals. Simulation results demonstrate that the proposed scheme achieves a significant PAPR reduction performance without data throughput loss as well as an improved BER performance when LED nonlinearity exists.

小波包变换对CO-OFDM系统高峰均比的抑制性能研究

小波包变换对CO-OFDM系统高峰均比的抑制性能研究

A Modified Approach Based On SLM for OFDM PAPR Reduction Using Time Domain SubBlock Conversion Matrix

OFDM is a digital transmission method developed to meet the increasing demand for higher data rates in communications which can be used in both wired and wireless environments. This thesis describes the issue of the PAPR in OFDM which is a major drawback, and presents new and variations to existing algorithms to reduce it. The effect on system performance in terms of the BER and Power Spectral Density is simulated for an OFDM transceiver with a saturated High Power Amplifier. A modified SLM approach based on time-domain sub-block conversion matrices to reduce the computational complexity due to multiple IFFTs. This scheme is modified from the conversion matrix scheme. By dividing the frequency-domain signals into multiple sub-blocks, the number of the valid conversion matrices can be increased, and thus more candidate signals are available for PAPR reduction. By applying proposed scheme, the number of candidate signals can be increased from 12 in the original conversion matrix scheme to 28 and 128 for the two sub block and four-sub block cases, respectively. The scheme will provide improved PAPR reduction performance.

A new low complexity technique for PAPR reduction by using peak-flipping

A major impediment for using OFDM is high peak-to-average power ratio PAPR, which significantly reduces the efficiency of high power amplifiers and increases power consumption. In this paper, we introduce a new and simple method for PAPR reduction by flipping the peaks of signals. Very low complexity, simple implementation, capability of good PAPR reduction and BER performance are the main advantages of this innovative approach. With this method there is no need to send any side information to the receiver for signal reconstruction. Due to the novel way, PAPR is reduced and increasing the number of carrier does not affect the complexity of the algorithm.