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![FIG. 2. The value of C tr − 1 [or 2( Ps tr − 1) according to Eq. (21)]...](profile/Jiangwei-Shang/publication/326968139/figure/fig2/AS:744146998403072@1554429878511/The-value-of-C-tr-1-or-2-Ps-tr-1-according-to-Eq-21-with-respect-to-the-two_Q320.jpg)
We show that a special type of measurements, called symmetric informationally complete positive operator-valued measures (SIC POVMs), provide a stronger entanglement detection criterion than the computable cross-norm or realignment criterion based on local orthogonal observables. As an illustration, we demonstrate the enhanced entanglement detectio...
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Existing 64-QAM Golay complementary pairs, each having impulse-like aperiodic auto-correlation sums, have been used to generate codebooks in code-keying orthogonal frequency-division multiplexing (OFDM) communications for the peak-to-mean power control. As a generalization of the 64-QAM Golay complementary pairs, in this paper, 64-QAM complementary...
Two of the most important techniques of Peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems are Partial Transmit Sequence PAPR (PTS-PAPR) and Cross-Correlation-PTS. This paper investigates a complete analysis on these two techniques providing simulation and discussion of their performance on PAP...
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... An important benefit about this group of techniques is that they do not need to transfer extra information to the receiver to inform about the modification performed on the signal at the transmitter. For many coding based techniques, such as [15,16], SLM [17], or PTS [18,19] based algorithms, the receiver has to be informed about the modifications performed on the signal at the receiver side, and generally, a compensation block has to be added to the receiver side to reverse the process, and this normally effects the symbol error rate (SER), and error vector magnitude (EVM). Moreover, informing the receiver normally involves transmitting extra bits as side information. ...
... It should be noted that if an algorithm requires complex multiplications, or complex divisions, they all have to be transformed into real multiplications and additions. For example, as mentioned earlier about SLM based techniques [17,20,36], at the receiver, a compensation block including a complex division is required in order to extract the original transmitted signal [37]. The second parameter that plays an important role in implementing a PAPR reduction technique in hardware is the the memory that is required. ...
... It should be noted that for techniques of PTS [18,[38][39][40], SLM based techniques [20,36,41], the set ups of the algorithms are considered in a way that the PAPR reduction performance is comparable with the PSI technique. This means that number of IDFT processed in both mentioned categories, is considered to be 16, and the length of the signal is considered to be 1024, which indicates the number of bts for storing the phases that are multiplied into the input signal [17,41]. Table 4. Computational complexity comparison. ...
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.
