82 research outputs found
A Low-Complexity SLM PAPR Reduction Scheme for OFDMA
In orthogonal frequency division multiplexing (OFDM) systems, selected mapping (SLM) techniques are widely used to minimize the peak to average power ratio (PAPR). The candidate signals are generated in the time domain by linearly mixing the original time-domain transmitted signal with numerous cyclic shift equivalents to reduce the amount of Inverse Fast Fourier Transform (IFFT) operations in typical SLM systems. The weighting factors and number of cyclic shifts, on the other hand, should be carefully chosen to guarantee that the elements of the appropriate frequency domain phase rotation vectors are of equal magnitude. A low-complexity expression is chosen from among these options to create the proposed low-complexity scheme, which only requires one IFFT. In comparison to the existing SLM technique, the new SLM scheme achieves equivalent PAPR reduction performance with significantly less computing complexity. MATLAB tool is used for simulating the proposed work
Digital signal processing techniques for peak-to-average power ratio mitigation in MIMO–OFDM systems
The focus of this thesis is to mitigate the very large peak-to-average
transmit power ratios (PAPRs) inherent to conventional orthogonal
frequency division multiplexing (OFDM) systems, particularly in the
context of transmission over multi-input multi-output (MIMO) wireless
broadband channels. This problem is important as a large PAPR
generally needs an expensive radio frequency (RF) power amplifier at
the transmitter due to the requirement for linear operation over a wide
amplitude range and such a cost would be compounded when multiple
transmit antennas are used. Advanced signal processing techniques
which can reduce PAPR whilst retain the integrity of digital transmission
therefore have considerable potential for application in emergent
MIMO–OFDM wireless systems and form the technical contributions
of this study. [Continues.
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