Fast peak-power reduction for MIMO-OFDM systems with diversity

peak-to-average power ratio (PAPR) reduction;peak-power reduction;Active Constellation Extension (ACE);Multiple input, multiple output (MIMO);Orthogonal frequency division multiplexing (OFDM)

Tsiligkaridis, Theodoros ; Jones, Douglas L. ; Jones ; Douglas L.

关键词: peak-to-average power ratio (PAPR) reduction;    peak-power reduction;    Active Constellation Extension (ACE);    Multiple input, multiple output (MIMO);    Orthogonal frequency division multiplexing (OFDM);   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/15304/Tsiligkaridis_Theodoros.pdf?sequence=2&isAllowed=y

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来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

A robust peak-power reduction technique called active constellation extension(ACE) reduces the peak-to-average power ratio (PAPR) of single-inputsingle-output (SISO) orthogonal frequency-division modulated (OFDM) signals byextending the outer constellation points in a way that minimizes the PAPR of anOFDM transmit signal, without reducing the bandwidth or increasing bit error rate(BER).Recent work includes extensions of the concept of ACE using a modi ed smartgradient-project algorithm for MIMO-OFDM systems. We extend the e cient ACEsmart gradient-project (SGP) method to space-time block coded (STBC),space-frequency block coded (SFBC) and V-BLAST OFDM systems. The proposedpeak-power reduction method can be applied to any space-time-frequency (STF)block code, and its performance is bounded by the code structure. Simulations showPAPR reduction gains of 4.19 and 3.57 dB under QPSK for Alamouti STBC andSFBC, respectively.In addition, we extend the e cient ACE-SGP method to rotatedconstellations for SISO-OFDM systems, an alternative method recently invented forproviding diversity. Simulation results show approximately 3.46 dB and 2.08 dB ofPAPR reduction for QPSK and 16-QAM original constellations, respectively, for256 subcarriers. Results also show that 4.29 dB and 3.41 dB of PAR reduction areobtained for QPSK and 16-QAM original constellations, respectively, for 1024subcarriers.Furthermore, we show how the PAPR reduction method known as toneinjection can be a very practical transmission scheme for coded-OFDM systems, with a slight compromise of the BER performance. This is accomplished bydeveloping e cient, near-optimal, convolutional and LDPC decoders for theextended non-bijective constellations introduced by tone injection. Simulationresults for convolutional and LDPC coded-OFDM systems show BER performancecomparable to conventional coded OFDM with greatly reduced PAPR.Furthermore, results show that the PAPR performance obtained is very close to the64-QAM single-carrier peak-power performance. So, the peak-power problem issolved for large constellations.