The majority in existing energy harvesting (EH) models utilize complex analysis and often overlook the memory effects of the system’s low-pass filter (LPF). In this work, we aim to fill this gap and propose a simple yet effective approach to model the receiver’s output and capture the LPF’s memory. Specifically, we analyze two fundamental circuits: the half-wave rectifier (HWR) and the diplexer-based receiver (DBR). By using circuit analysis, we derive mathematical models for each receiver’s output, validated through circuit simulations. We then investigate these models in the context of integrated simultaneous wireless information and power transfer (SWIPT) receivers. For the HWR, we consider amplitude modulation and, using communication theory tools, we evaluate the performance in terms of bit error rate (BER) for both maximum likelihood (ML) and ML sequence detection (MLSD) schemes. Our results reveal the impact of memory-induced intersymbol interference on the BER and indicate that MLSD is necessary towards achieving higher data rates. For the DBR, we show that its LPF exhibits similar characteristics to the HWR yet is able to achieve better EH performance due to the lack of signal splitting. Finally, we explore the DBR’s band-pass filter output for information decoding, highlighting its capability to also use phase modulation. Clearly the DBR stands out as a more flexible receiver, while the HWR’s simple design makes it ideal for devices with limited resources.

Sixth generation networks will establish the terahertz (THz) era, introducing numerous potential applications for wireless power transfer (WPT). In this work, we focus on a fluid-antenna (FA)-aided WPT system which operates over the THz bands, featuring a non-monotonic diode-based rectifier. By taking into account the circuit's unconventional behavior, we first exploit a linear piece-wise function to approximate rectifier's input-output power relationship. Based on this, we provide an analytical framework in terms of the energy outage probability for three FA port selection (PS) schemes, namely (i) the input-based selection, (ii) the harvesting-based selection, and (iii) the random selection, each corresponding to different complexity and performance. Numerical results which validate our analysis, reveal a novel utilization of FAs, stemming from the alignment of the PS process with the non-monotonic harvesting characteristics.

Wireless power transfer has been proposed as a key technology for the foreseen machine type networks. A main challenge in the research community lies in acquiring a simple yet accurate model to capture the energy harvesting performance. In this work, we focus on a half-wave rectifier and based on circuit analysis we provide the actual output of the circuit which accounts for the memory introduced by the capacitor. The provided expressions are also validated through circuit simulations on ADS. Then, the half-wave rectifier is used as an integrated simultaneous wireless information and power transfer receiver where the circuit's output is used for decoding information based on amplitude modulation. We investigate the bit error rate performance based on two detection schemes: (i) symbol-by-symbol maximum likelihood (ML); and (ii) ML sequence detection (MLSD). We show that the symbol period is critical due to the intersymbol interference induced by circuit. Our results reveal that MLSD is necessary towards improving the error probability and achieving higher data rates.

The future sixth generation (6G) wireless communications are envisioned to bring forth the era of the Internet of Everything (IoE). This work investigates wireless power transfer (WPT) in the radiating near-field region, as a medium for charging the low-powered IoE devices. Specifically, we exploit the near- field channel model in order to create power beamfocusing at a predefined focal point. We consider a uniform planar array employing beamfocusing, and provide analytical expressions for the harvested power at the receiver located at (i) a fixed and (ii) a random location in the network. We present numerical results which validate our analysis and draw an insight overview for the near-field WPT under various design parameters while demonstrating the gains brought against far-field WPT.

Rate splitting (RS) and wireless edge caching are essential means for meeting the quality of service requirements of future wireless networks. In this work, we focus on the cross-layer co-design of wireless edge caching schemes with sophisticated physical layer techniques, which facilitate non-orthogonal multiple access and interference mitigation. A flexible caching-aided RS (CRS) technique is proposed that operates in various modes that specify the cache placement at the receivers. We consider two caching policies: the intelligent coded caching (CC), as well as the well-known most popular content (MPC) policy. Both caching policies are integrated within the design parameters of RS in order to serve multiple cache-enabled receivers. The proposed technique is investigated from a system level perspective by taking into account spatial randomness. We consider a single cell network consisting of center and edge receivers and provide a comprehensive analytical framework for the evaluation of the proposed technique in terms of achieved rates. Specifically, we derive the rate achieved at each receiver under minimum rate constraints while incorporating the cache placement characteristics. Numerical results are presented which highlight the flexibility of the proposed technique and show how caching can be exploited in order to further boost the performance of RS.

LoRa networks have been deployed all over the world and are a major enabling wireless technology for the Internet of Things (IoT). Massive connectivity applications such as smart metering, agriculture, and supply chain & logistics are most suitable for LoRa deployments due to their long range, low cost, and low power features. Meanwhile, energy harvesting technologies that extract energy from ambient sources have enabled the battery-less operation of many small wireless sensors. This paper studies the merger of these two technologies and mathematically models device and network performance using tools from stochastic geometry and Markov analysis. To that end, we derive the steady-state distribution of the capacitor voltage, the outage probability due to co-spreading factor interference at the LoRa gateway, and propose adaptive charging time schemes in order to mitigate energy outage events.

Handover and mobility management are important and critical aspects of future ultra-dense cellular networks. This paper proposes an intelligent handover technique, which reduces the handover rate without significant performance losses. Specifically, we investigate a user-centric handover scheme that exploits base station (BS) cooperation to enable a dynamic handover skipping. By considering mobility awareness, the users skip some handover executions and remain connected with at least a single BS. In this way, we achieve a balance between BS cooperative transmissions and single BS transmission to reduce handover rate and consequently the associated signal overhead. Our results show that the proposed scheme outperforms conventional solutions in terms of the average user throughput, particularly for high velocities and ultra-dense networks.