The Internet of Things (IoT) architecture is quickly becoming popular even outside of its originating scenario of home automation. This paper reports the design, implementation, and performance of an IoT hardware and software architecture conceived for the continuous monitoring of livestock located in barns and during grazing. We have adopted the LoRa low power wide area network (LPWAN) technology to cover the diverse environments, and a suitable configuration of web services to perform data storage, analysis, and visualization. Since the LoRa LPWAN (LoRaWAN) medium access control (MAC) layer does not provide a listen-before-talk (LBT) mechanism, we propose a custom MAC layer with LBT-based carrier-sense multiple access with collision avoidance (CSMA/CA). The devised system has been implemented using off-the-shelf hardware, and its performance has also been estimated with the help of a C++ event-based simulator. The preliminary results of our HW implementation on the field confirm the stability of the conceived system and its reliability.

This article proposes new approximations for the bit error probability of several LoRa-based schemes, such as phase-shift keying (PSK) LoRa, in-phase and quadrature (IQ) chirp spread spectrum (CSS), discrete chirp rate keying (DCRK) CSS, and CSS with index modulation (IM). We include a new scheme that combines IQ, CSS, and IM, denoted as IQ chirp index modulation (IQCIM). Our analysis, which assumes coherent detection in additive white Gaussian noise, compares the LoRa-based schemes also in terms of spectral efficiency, computational complexity, and peak-to-average power ratio (PAPR). Noncoherent detection of CSS with IM is analyzed as well. Our performance analysis shows that the proposed IQCIM produces a significant increase of spectral efficiency (SE) compared to LoRa with similar complexity, at an energy cost of approximately 0.9 dB. When compared to the other LoRa-based schemes, for a fixed decoding latency, the SE of IQCIM is still the largest, with reduced computational cost per transmitted bit. In this context, we also propose a maximum-likelihood (ML) coherent detector for PSK-LoRa and a novel noncoherent detector for IQCSS.

The seamless integration of multiple radio access technologies (multi-RAT) and cloud/edge resources is pivotal for advancing future networks, which seek to unify distributed and heterogeneous computing and communication resources into a cohesive continuum system, tailored for mobile applications. Many research projects and focused studies are proposing solutions in this area, the impact of which is undoubtedly increased by moving from theoretical and simulation studies to experimental validations. To this aim, this paper proposes a testbed architecture that combines contemporary communication and cloud technologies to provide microservice-based mobile applications with the ability to offload part of their tasks to cloud/edge data centers connected by multi-RAT cellular networks. The testbed leverages Kubernetes, Istio service mesh, OpenFlow, public 5G networks, and IEEE 802.11ad mmWave (60 GHz) Wi-Fi access points. The architecture is validated through a use case in which a ground robot autonomously follows a moving object by using an artificial intelligence-driven computer vision application. Computationally intensive navigation tasks are offloaded by the robot to microservice instances, which are executed on demand within cloud and edge data centers that the robot can exploit during its journey. The proposed testbed is flexible and can be reused to assess communication and cloud innovations focusing on multi-RAT cloud continuum scenarios.

We derive new bounds on the symbol error probability (SEP) of M-ary phase-shift keying (MPSK) with M>4, in additive white Gaussian noise. The exact SEP expressions require numerical integration or the computation of a two-dimensional function. Differently, the new SEP bounds only depend on simple one-dimensional functions and hence are easier to compute than the exact SEP. We show that the new bounds are tighter than the existing SEP bounds for MPSK at low signal-to-noise ratio (SNR), while preserving accuracy at large SNR. In addition, simple and accurate SEP approximations for MPSK with M>4 are derived.

This paper presents a feasibility study for a very high data rate receiver operating in the K/Ka-band suitable to future Moon exploration missions. The receiver specifications are outlined starting from the mission scenario and from a careful system analysis. The designed architecture uses a low noise front-end to down-convert the incoming K/Ka-band signal into a $3.7\mathrm{GHz}$ intermediate frequency (IF). For maximum flexibility, a software defined radio (SDR) is adopted for the I/Q demodulation and for the analog to digital conversion (ADC). The decoding operations and the data interface are carried out by a processor based on field programmable gate array (FPGA) circuits. To experimentally verify the above concepts, a preliminary front-end breadboard is implemented, operating between 27.5 and 30 GHz. The breadboard, which uses components off the shelf (COTS) and evaluation boards (EVBs), is characterized by a $46\mathrm{dB}$ gain, a $3.4\mathrm{dB}$ noise figure and a $-37\mathrm{dBm}$ input-referred 1 dB compression point. Finally, a $40\mathrm{Msym}/\mathrm{s}$ quadrature phase shift keying (QPSK) signal is demodulated by means of a commercially available SDR, demonstrating the above concept. The importance of these results is that they have been obtained exploiting a class of miniaturized and low cost microwave integrated circuits currently available on the market, opening the way to a dense communication infrastructure on cislunar space.