FPGA Implementation of Inverse Fast Fourier Transform in Orthogonal Frequency Division Multiplexing Systems

Mohammady, Somayeh; Sulaiman, Nasri; Sidek, Roslina Mohd; Varahram, Pooria; Hamidon, Mohd Nizar

doi:10.5772/36664

Cited by 3 publications

(3 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A block diagram of OFDM is presented in Figure 1, which presents the process of generating orthogonal frequency division multiplexing (OFDM) at the transmitter and the receiver. The orthogonality characteristic is provided by Fourier transform which is applied to signal in form of inverse and discrete as IDFT in transmitter part, and as discrete form as DFT in the receiver part [8]. As result of Fourier transform, there are construction and destruction effects and some signal peaks cancel each other, and some add which creates high peaks in the time domain.…”

Section: Fast Fourier Transform; Origin Of High Peak To Average Powermentioning

confidence: 99%

“…, Ph.M) are multiplied into the signal. The received signal at the receiver has to be divided by the same phase in order to extract the original signal, this means implementing a complex division block at the receiver, which has its own complications, as explained in [21]. There are some works aimed at improving these complications [22,23] and the authors have designed algorithms to avoid transferring extra bits; however, the complexity at the transmitter, and the channel security, remain challenging.…”

Section: Previous Peak To Average Power Ratio or Crest Factor Reductimentioning

confidence: 99%

See 1 more Smart Citation

Performance Investigation of Peak Shrinking and Interpolating the PAPR Reduction Technique for LTE-Advance and 5G Signals

et al. 2019

Self Cite

View full text Add to dashboard Cite

Orthogonal frequency division multiplexing (OFDM) has become an indispensable part of waveform generation in wideband digital communication since its first appearance in digital audio broadcasting (DAB) in Europe in 1980s, and it is indeed in use. As has been seen, the OFDM based waveforms work well with time division duplex operation in new radio (NR) systems in 5G systems, supporting delay-sensitive applications, high spectral efficiency, massive multiple input multiple output (MIMO) compatibility, and ever-larger bandwidth signals, which has demonstrated successful commercial implementation for 5G downlinks and uplinks up to 256-QAM modulation schemes. However, the OFDM waveforms suffer from high peak to average power ratio (PAPR), which is not desired by system designers as they want RF power amplifiers (PAs) to operate with high efficiency. Although NR offers some options for maintaining the efficiency and spectral demand, such as cyclic prefix based (CP-OFDM), and discrete Fourier transform spread based (DFT-S-OFDM) schemes, which have limiting effects on PAPR, the PAPR is still as high as 13 dB. This value increases when the bandwidth is increased. Moreover, in LTE-Advance and 5G systems, in order to increase the bandwidth, and data-rate, carrier aggregation technology is used which increases the PAPR the same way that bandwidth increment does; therefore, it is essential to employ PAPR reduction in signal processing stage before passing the signal to PA. In this paper, we investigate the performance of an innovative peak shrinking and interpolation (PSI) technique for reducing peak to average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) based signals at waveform generation stage. The main idea behind the PSI technique is to extract high peaks, scale them down, and interpolate them back into the signal. It is shown that PSI technique is a possible candidate for reducing PAPR without compromising on computational complexity, compatible for existing and future telecommunication systems such as 4G, 5G, and beyond. In this paper, the PSI technique is tested with variety of signals in terms of inverse fast Fourier transform (IFFT) length, type of the signal modulation, and applications. Additional work has been carried out to compare the proposed technique with other promising PAPR reduction techniques. This paper further validates the PSI technique through experimental measurement with a power amplifier (PA) test bench and achieves an adjacent channel power ratio (ACPR) of less than -55 dBc. Results showed improvement in output power of PA versus given input power, and furthermore, the error vector magnitude (EVM) of less than 1% was achieved when comparing of the signal after and before modification by the PSI technique.

show abstract

Section: Fast Fourier Transform; Origin Of High Peak To Average Powermentioning

confidence: 99%

Section: Previous Peak To Average Power Ratio or Crest Factor Reductimentioning

confidence: 99%

Performance Investigation of Peak Shrinking and Interpolating the PAPR Reduction Technique for LTE-Advance and 5G Signals

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…One particular example for application of multiplexing is seen in orthogonal frequency division multiplexing (OFDM) systems [10]. The signal is spread between different subcarriers, and the frequency bandwidth is efficiently used [11].…”

Section: Author Detailsmentioning

confidence: 99%

Introductory Chapter: Multiplexing History - How It Applies to Current Technologies

Mohammady¹,

Varahram²

2019

Multiplexing

Self Cite

View full text Add to dashboard Cite

FPGA implementation of low complexity crest factor reduction in OFDM systems

Mohammady

Sulaiman

Sidek

et al. 2013

2013 IEEE 11th Malaysia International Conference on Communications (MICC)

View full text Add to dashboard Cite

DSI) is implemented on FPGA. The aim of this OPS-DSI scheme is to enhance the PAPR performance, increase the flexibility of the design and reduce the transmission complexity. In this paper, FPGA implementation of the OPS-DSI scheme is carried out and the results are compared with the simulation results. The transmission system is designed based on the IEEE 802.16e standard with 256 Inverse Fast Fourier Transform (IFFT) length and QPSK modulation.

show abstract

FPGA Implementation of Inverse Fast Fourier Transform in Orthogonal Frequency Division Multiplexing Systems

Cited by 3 publications

References 37 publications

Performance Investigation of Peak Shrinking and Interpolating the PAPR Reduction Technique for LTE-Advance and 5G Signals

Performance Investigation of Peak Shrinking and Interpolating the PAPR Reduction Technique for LTE-Advance and 5G Signals

Introductory Chapter: Multiplexing History - How It Applies to Current Technologies

FPGA implementation of low complexity crest factor reduction in OFDM systems

Contact Info

Product

Resources

About