Peak-to-average power reduction in space division multiplexing based OFDM systems through spatial shifting

Reduction of Nonlinear Distortion in Multi-Antenna WiMAX Systems

“…The algorithm concentrates on the antenna exhibiting the highest PAPR and aims to reduce it Siegel & Fischer (2008). In contrast to afore mentioned approaches, Spatial shifting provides additional way to exploit presence of multiple antenna by cyclically shifting the partial sequences between antennas Schenk et al (2005). In other words, instead of using weighting factors for generating the different signal representations cyclic shifting of the partial sequences between the antennas is used.…”

SOCP Approach for Reducing PAPR for MIMO-OFDM Via Tone Reservation

“…On the other hand, the PAPR limits seriously the power efficiency of the transmitter's High Power Amplifier (HPA). Thus, many techniques have been proposed to deal with the PAPR problem [5][6][7][8][9][10][11]. These techniques include amplitude clipping, clipping and filtering, coding, tone reservation, tone injection, active constellation extension, and multiple signal representation techniques such as partial transmit sequence, selected mapping, and interleaving.…”

A Novel PAPR Reduction Method in MIMO-OFDM Systems by Frequency Block Exploitations

“…Previous researches include SLM and PTS based on space-time block code (STBC) with space-time block structure (for emphasizing the distinction from space-frequency structure) in MIMO-OFDM system [2][3], nonlinear precoding [4], spatial shifting [5], and cross-antenna rotation and inversion [6]. In [4], the author makes use of the redundant constellation positions of precoded signal to improve PAPR property with complex sphere precoder.…”

“…But the computational complexity is very high. In [5], PTS method is considered, and using rotating the corresponding PTS subblocks at all transmit antennas to obtain choice space. However, the performance is not good enough.…”

“…But the performance gain almost will not increase even though the subblock number is not large. Explicitly or implicitly, the most typical methods above [2][3] [5][6] make use of spacetime block framework for its inherit encoding structure property. It is noticed that vector X and ±X * have the same PAPR character [6].…”