Companding schemes based on transforming signal statistics into trigonal distributions for PAPR reduction in OFDM systems

This paper proposed a modified tone reservation (TR) technique that can reduce the peak-to-average power ratio (PAPR) of the orthogonal frequency division multiplexing (OFDM) system and is able to correct errors to avoid channel interference. The TR technique is a widely used PAPR reduction technique, which divides subcarriers of the OFDM system into two sets to generate peak-canceling signals and transmit modulated data. The subcarriers used to reduce the PAPR are called the peak reduction tone sets. The mechanism of peak-canceling signal generation is a primary factor in determining the quality of the PAPR reduction performance of the TR technique. Currently, two signal generation mechanisms exist: TR-gradient-based and TR-clipping-based techniques. Although TR techniques can effectively reduce the high PAPR in the OFDM system, TR techniques lack the ability to correct errors. Therefore, this paper combined block coded modulation codes and TR techniques to provide the modified TR techniques with error correction abilities. From the simulation results, the modified TR techniques had a superior effect on PAPR reduction performance compared with the conventional TR technique. The modified TR technique also possessed the ability to correct errors during signal transmission. 749Numerous techniques improving the high PAPR of the OFDM system have been proposed successively [6], such as amplitude clipping [7], partial transmit sequence (PTS) [8,9], selected mapping (SLM) [10,11], and tone reservation (TR) [12][13][14][15][16]. The amplitude clipping technique adopts the method of filtering signals to reduce the high PAPR. In other words, with a predetermined transmitted signal amplitude threshold, the amplitude clipping technique replaces the transmitted signal amplitude with the threshold when the transmitted signal amplitude is higher than the threshold; conversely, the original transmitted signal is used for transmission when the transmitted signal amplitude is lower than or equal to the threshold. Because the amplitude clipping technique easily induces distortion of transmitted signals, massive calculations must be conducted at the receiving end to improve distortion. Meanwhile, PTS and SLM techniques are categorized as multiple signal representation (MSR) techniques that generate multiple sets of candidate signals, using phase changes during signal transmission and selecting the signal with the minimum PAPR from candidate signals for transmission. Although PTS and SLM techniques can effectively reduce the high PAPR, side information (SI) must be transmitted from the transmission end to the receiving end to identify the candidate signal selected for transmission, thereby facilitating a precise and perfect recovery of transmitted data at the receiving end. The TR technique can also be considered as an MSR technique. However, in contrast to PTS and SLM techniques, the TR technique does not need to transmit additional SI to the receiving end. The TR technique reserves a number of the subcarriers ready to transmit data...

Section: Tone Reservation-reed-mullermentioning

confidence: 99%

Section: Tone Reservation-reed-mullermentioning

confidence: 99%

Section: Tone Reservation-block Coded Modulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Peak‐to‐average power ratio reduction of orthogonal frequency division multiplexing systems using modified tone reservation techniques

Liang

Chu

Lin

2015

“…3. M-TR SCHEME Various methods [9][10][11][12][13][14][15][16][17][18] have been proposed to reduce the PAPR of OFDM signals, among them, the TR method is an attractive one because it can achieve significant PAPR reduction without side information and signal distortion. In the TR method, transceiver agrees on reserving a small set of tones for generating peak reduction signals for PAPR reduction.…”

Section: Sfbc Mimo-ofdm Systemsmentioning

confidence: 99%

Peak‐to‐average power ratio reduction in space frequency block coding multi‐input multi‐output orthogonal frequency division multiplexing systems by tone reservation

Deng

Jiang

Zhou

et al. 2013

SUMMARY In this paper, a tone reservation (TR) method is employed to reduce the peak‐to‐average power ratio (PAPR) in multi‐input multi‐output orthogonal frequency division multiplexing systems with space frequency block coding (SFBC). The key idea of the employed TR method is taking signals on multiple transmit antennas into account to design appropriate peak reduction symbols, which can significantly reduce the PAPR of SFBC multi‐input multi‐output orthogonal frequency division multiplexing signals. With the employed TR scheme, the SFBC structure can be maintained, whereas the traditional TR method would destroy it, resulting in the degradation of bit error rate (BER) performance. Simulation results demonstrate that the employed TR scheme can provide significantly better BER performance than the traditional TR method with slight PAPR reduction degradation. Copyright © 2013 John Wiley & Sons, Ltd.

A partial transmit sequence technique with error correction capability and low computation

Liang

Chu

Lin

et al. 2013

SUMMARYOrthogonal frequency division multiplexing (OFDM) is a popular transmission technique in wireless communication. Although already widely addressed in many studies, OFDM still has flaws, one of which is the occurrence of high peak-to-average power ratio (PAPR) in the transmission signal. The partial transmit sequence (PTS) technique is one method adopted to reduce high PAPR in OFDM systems. However, as PTS utilizes phase factors to generate multiple candidate signals, large amounts of calculation and time are required to search the candidate signal with the minimal PAPR, which will then be adopted as the final transmission signal. This paper proposes a novel PAPR reduction method, which can be applied in OFDM systems with M-ary phase-shift keying modulation. It not only requires less computation but also possesses error correction capabilities. More precisely, the proposed method is to divide a block-coded modulation code into the direct sum of a correcting subcode for encoding information bits and a scrambling subcode for generating phase factors. Our proposed method is a suboptimal technique with low computation, because it uses a genetic algorithm with a partheno-crossover operator as the transmitted signal selection mechanism. Simulation results show our proposed method has better PAPR performance than the GA-PTS scheme. Based on the simulation results in Figures 5 and 6, it is evident that our proposed method can be employed in any OFDM system by using M-PSK modulation.