SIMO subcarrier PSK FSO links with phase noise and non‐zero boresight pointing errors over turbulence channels

Transdermal Optical Wireless Links with Multiple Receivers in the Presence of Skin-Induced Attenuation and Pointing Errors

“…where in each link it holds that [39,41,46,58]. Here, it becomes evident that the impact of pointing errors effect is getting stronger as the value of ψ m parameter decreases.…”

“…FSO communication link, and thus, random atmospheric channel's impairments have been addressed, such as atmospheric turbulence-induced signal's fading [2,4,46], while in [2] L-PPM signaling technique has been proposed in order to achieve further such performance enhancements. However, for a TOW link which is investigated in this work, there is an essential difference concerning the nature of the transmission medium.…”

“…Nevertheless, NZB pointing errors had never been examined in TOW literature, just as no method had been proposed in order to enhance the TOW outage performance and availability. Only, very recently, authors demonstrated for the first time, in [39], that a diversity method-i.e., in space, in time, or in wavelength-is an effective technique to enhance the outage performance of a typical TOW in terms of outage probability metric, by considering the joint impact of both attenuation-induced fading and misalignment-induced fading with NZB, modeled by the accurate Beckmann distribution [3,[41][42][43][44][45][46]. In basic terms, diversity refers to the consideration of multiple copies of the propagated signals in an attempt to overcome a poor transmission media state so as to reinforce the communication link's availability and robustness.…”

“…Motivated by these facts, a key novelty in this work is the estimation of the ABER performance of a SIMO TOW system that may employ apart from OOK, L-PPM modulation format alike, under the joint impact of skin-induced attenuation and pointing errors with non-zero boresight. It should be highlighted here that in previous published works concerning FSO, receiver's diversity in terms of SIMO configurations have been used in order to enhance the performance of a terrestrial, outdoor FSO communication link, and thus, random atmospheric channel's impairments have been addressed, such as atmospheric turbulence-induced signal's fading [2,4,46], while in [2] L-PPM signaling technique has been proposed in order to achieve further such performance enhancements. However, for a TOW link which is investigated in this work, there is an essential difference concerning the nature of the transmission medium.…”

“…In short, although SIMO and L-PPM techniques have been also considered in outdoor FSO communications, this is the first time that both techniques are applied this way in the biomedical and transdermal communication systems where the requirements for very low energy consumption and negligible biological effects must be fully met. Thus, motivated and inspired by our previous works in outdoor FSO [2,4,46], in the current work we introduce, for the first time ever, SIMO with L-PPM in an entirely different field of optical wireless communications-i.e., transdermal optical communications with medical implants-as an attempt to enhance the outage probability of such systems. Thus, the scope of this work is to outbalance the negative side-effects of this joint impact by introducing L-PPM SIMO TOW configurations.…”