Computer Science – Information Theory
Scientific paper
2010-02-07
Computer Science
Information Theory
Scientific paper
Active Constellation Extension (ACE) is one of techniques introduced for Peak to Average Power Ratio (PAPR) reduction for OFDM systems. In this technique, the constellation points are extended such that the PAPR is minimized but the minimum distance of the constellation points does not decrease. In this paper, an iterative ACE method is extended to spatially encoded OFDM systems. The proposed methods are such that the PAPR is reduced simultaneously at all antennas, while the spatial encoding relationships still hold. It will be shown that the original ACE method can be employed before Space Time Block Coding (STBC). But in case of Space Frequency Block Coding (SFBC), two modified techniques have been proposed. In the first method, the OFDM frame is separated by several subframes and the ACE method is applied to these subframes independently to reduce their corresponding PAPRs. Then the low PAPR subframes are recombined based on SFBC relationships to yield the transmitted signals from different antennas. In the second method, for each iteration, the ACE is applied to the antenna with the maximum PAPR, and the signals of the other antennas are generated from that of this antenna. Simulation results show that both algorithms converge, but the second method outperforms the first one when the number of antennas is increased.
Marvasti Farokh
Naeiny Mahmoud Ferdosizadeh
No associations
LandOfFree
PAPR reduction of space-time and space-frequency coded OFDM systems using active constellation extension does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with PAPR reduction of space-time and space-frequency coded OFDM systems using active constellation extension, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and PAPR reduction of space-time and space-frequency coded OFDM systems using active constellation extension will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-582740