Title :
Differential Decoding of SIM DPSK over FSO MIMO Links
Author_Institution :
Dept. of Electr. Eng., Indian Inst. of Technol. Delhi, New Delhi, India
Abstract :
In this paper, we derive a differential decoder for the subcarrier intensity modulation (SIM) based differential phase shift keying (DPSK) scheme in free space optical (FSO) multiple-input multiple-output (MIMO) communication system. The proposed differential decoder avoids requirement of the knowledge of irradiance fluctuations in the receiver contrary to the existing selection combining (SC) based decoder of SIM DPSK. Moreover, the proposed differential decoder enables the SIM DPSK scheme to outperform the non-coherent decoding based pulse position modulation scheme. We theoretically analyze the bit error rate (BER) performance of the SIM differential binary phase shift keying modulation scheme with differential decoding over FSO MIMO links which follow the Gamma-Gamma distribution. On the basis of the analytical BER, the analytical diversity order of the proposed differential decoder is obtained.
Keywords :
MIMO communication; decoding; differential phase shift keying; diversity reception; gamma distribution; optical communication; optical links; optical modulation; pulse position modulation; BER performance; FSO MIMO link; Gamma-Gamma distribution; SIM DPSK scheme; bit error rate performance; differential decoding; diversity order; free space optical multiple-input multiple-output communication system; irradiance fluctuations; noncoherent decoding-based pulse position modulation scheme; phase shift keying; selection combining-based decoder; subcarrier intensity modulation; Apertures; Decoding; Differential phase shift keying; MIMO; Phase shift keying; Receivers; Signal to noise ratio; Differential modulation; Gamma-Gamma fading; free space optical links; multiple-input multiple-output (MIMO) system;
Journal_Title :
Communications Letters, IEEE
DOI :
10.1109/LCOMM.2012.112012.121920
