Performance analysis of coherent wireless optical communications with atmospheric turbulence

Abstract

Coherent wireless optical communication systems with heterodyne detection are analyzed for binary phase-shift keying (BPSK), differential PSK (DPSK), and M-ary PSK over Gamma-Gamma turbulence channels. Closed-form error rate expressions are derived using a series expansion approach. It is shown that, in the special case of K-distributed turbulence channel, the DPSK incurs a 3 dB signal-to-noise ratio (SNR) penalty compared to BPSK in the large SNR regime. The outage probability is also obtained, and a detailed outage truncation error analysis is presented and used to assess the accuracy in system performance estimation. It is shown that our series error rate expressions are simple to use and highly accurate for practical system performance estimation.

Performance Analysis of Heterodyne-Detected OCDMA Systems Using PolSK Modulation over a Free-Space Optical Turbulence Channel

“…The detailed parameters of the value are shown in Table 1. As with previous studies on the operation principle of coherent detection technology [23], the power of LO is assumed to be sufficiently high compared to the received signal power, P LO P R , where P R is characterized by the received optical power. The shot noise can then be calculated as σ 2 shot ≈ 2q P LO B 0 in later calculation.…”

Alamouti-Type STBC for Atmospheric Optical Communication Using Coherent Detection

“…In (39), Ã denotes the convolution operator, and a ½x p ð; Þ denotes the convolution of a p ð; Þ with itself x À 1 times, e.g., a ½2 p ð; Þ ¼ a p ð; Þ Ã a p ð; Þ. Specifically, we have a ½0 p ð; Þ ¼ 1 and a ½1 p ð; Þ ¼ a p ð; Þ.…”

Subcarrier Intensity Modulated Optical Wireless Communications Using Noncoherent and Differentially Coherent Modulations

“…The subcarrier signal at the output of the electrical modulator can be written as (1) where denotes the real part of a complex-valued quantity, is the carrier frequency of the subcarrier signal, , and is a generic low-pass equivalent signal having the form of (2) where is the amplitude. For differentially coherent phase-shift keying, the phase , where is the modulation order, will convey the transmitted information and is set to be 0.…”

“…On-off keying (OOK) with irradiance modulation and direct detection (IM/DD) is commonly used because it is simple to implement, although its performance is worse than other types of OWC systems. On the other hand, spatially coherent OWC systems using phase-shift keying (PSK) with phase compensation can offer excellent background noise rejection capability and high receiver sensitivity at the cost of much higher complexity (refer to [1], [2], and the references therein). Coherent optical polarization modulated system is another option which can provide improved link performance with increased system complexity.…”