Bi‐directional relay‐assisted FSO communication systems over strong turbulence channels with pointing errors

Abstract

SUMMARYThis paper presents the capacity and average bit error rate (BER)-based performance analysis of a two-way relay-assisted free-space optical communication system, over an atmospheric turbulent channel modeled by the Gamma-Gamma distribution and also affected by path loss and misalignment errors. A half-duplex, decode-and-forward, two-way, optical relay is considered, which establishes communication between two terminals, when direct communication is not possible because of non line-of-sight propagation or large distance. For the presented system and channel models and considering heterodyne detection at the receiver, we formulate the statistics of the instantaneous signal-to-noise ratio, followed by calculation of exact analytical expressions of capacity and BER. The mathematical expressions are formulated in terms of easily computable Meijer's G-function. This mathematical analysis is accompanied with several numerical examples to illustrate the effect of the key system parameters.

Optimizing mmWave Wireless Backhaul Scheduling

“…In this section, we prove that the decision version 4 of the MMWBS problem is NP-hard, even if there is no interference and K = 1 5 . The proof is via a reduction from the partition problem with equal cardinality (PEC): Given 2n natural numbers a 1 , a 2 , .…”

“…1 illustrates this approach, which is the reference scenario used in this paper. Since it can be adapted at millisecond time scales and includes costs and advantages of beamsteering in the loop, the mmWave relay case is very different from other relay optimization problems studied in the literature and involving, e.g., WLAN, cellular and satellite networks [4] or free-space optical links [5]. The possibility of relaying and the availability of multiple antenna elements make possible communication speedups as described above, but also increase the complexity of scheduling data for delivery, as one needs to choose whether to relay or not, to which µBSs, and which MBS links must be used.…”

Coverage Optimization with a Dynamic Network of Drone Relays

“…Figure 4.1 illustrates this approach, which is the reference scenario used in this chapter. Since it can be adapted at millisecond time scales and includes costs and advantages of beamsteering in the loop, the mmWave relay case is very different from other relay optimization problems studied in the literature and involving, e.g., WLANs, cellular and satellite networks [96] or free-space optical links [97].…”

Effects of pointing errors and channel fading on the performance of free‐space optically‐preamplified PPM systems

“…Systems with OOK modulation and DD receivers over double‐generalized gamma fading channels were studied in . While many studies addressed the combined effects of pointing errors and channel fading , or the pointing errors alone , on the performance of FSO systems, none of them considered optically preamplified DD M ‐ary PPM systems.…”

“…Systems with OOK modulation and DD receivers over double-generalized gamma fading channels were studied in [16]. While many studies addressed the combined effects of pointing errors and channel fading [19][20][21][22][23][43][44][45][46][47], or the pointing errors alone [48], on the performance of FSO systems, none of them considered optically preamplified DD M -ary PPM systems.In this paper, we study the performance of inter-satellite links that use M -ary PPM systems with optical preamplification and that are subjected to pointing errors. We also study the performance of inter-building links that use the same optically preamplified M -ary PPM systems in the presence of both pointing errors and slow channel fading.…”