Satellite communications play an important role in future Internet of Things (IoT) networks, and megasatellite constellations can further provide global coverage high-quality services for IoT communications. In the megaconstellation, large-scale satellites are launched to enhance capacity. However, dense distribution brings intraconstellation interference, limiting performance. order evaluate restriction interference caused by system parameters, such as scale constellation or frequency reuse...

In the mega constellation, hundreds of satellites are launched into space to provide global coverage and high-quality service. The number served user terminals (UTs) can be large-scale under such a dense distribution satellites, which may lead severe intra-constellation interference in uplink communications. Hence, it is quite necessary analyze deduce analytical expressions performance constellations design principles for constellation construction. this paper, we investigate terms outage...

We consider the uplink connectivity for massive machine-type communications (mMTC) assisted by intelligent reconfigurable surfaces (IRSs), where device activity detection (DAD) and channel estimation (CE) are challenging due to limited pilot sequences. Moreover, differentiation among types causes channels deviate from assumed characteristics, leading performance degradation of conventional compressive sensing (CS) algorithms. To this end, two innovative networks driven hybrid model data...

In helicopter satellite communication systems, the received signal is blocked by rotor blades during propagation, incurring unstableness of traditional methods channel estimation due to unknown state. To this end, a joint occlusion detection and phase algorithm proposed factor graph in paper. For acquire state, model established relying on Markov chain with priori blocking ratio, which probability distribution state calculated message-passing algorithm. obtain position update...

In non-geostationary orbit (NGSO) satellite networks, users perform random access (RA) to establish connections. Due the non-uniform traffic demands of RA in time and space, dynamic control resource allocation methods with low signaling overhead high efficiency are required, where is denoted as number successfully accessed per block. Existing adjustment provide a feasible approach improve short update intervals, but frequent updates these result overhead. Compared short-term update, given...

In satellite communications, the power amplifier (PA) plays a vital role in enhancing transmission performance of signals. However, non-linearity PAs often distorts transmitted signals, degrading communication performance. Digital pre-distortion (DPD) is one most effective linearization technologies to address abovementioned issue and improve PA Neural networks (NNs) outperform traditional models behavioral modeling due their strong nonlinear fitting capability, but lack learning data...

Grant-free non-orthogonal multiple access (NOMA) is highly expected to support massive connectivity and reduce the transmission latency for future wireless communications. In this paper, we present a joint active user data detection with no priori knowledge of users relying on expectation propagation (EP) Gaussian approximation (GA) algorithm. To detect activity, structured spike slab prior introduced sparsity signal. Further, parameters unknown are learned via maximization (EM), which...

Wi-Fi-based Human action recognition (HAR), as significant support for the loT applications, such human-computer interaction, healthcare, etc. is attracting attention of more and researchers. With rapid development deep learning (DL), DL-based HAR methods achieve excellent performance. Even though, generalization performance cross-environment still a challenge. Previous work relies on collecting sufficient data in different environments, which time-consuming labor-constraint. To address this...

Random access is a key technology in satellite communication, as large number of machine- type communication (MTC) terminals accessing the makes it difficult to guarantee quality. Irregular repetition slotted ALOHA (IRSA) one random protocol relying on transmitting irregular replicas multiple time slots, achieving peak throughput at 0.8 practical implementations. However, probability sending certain stays same when given degree distribution, without considering effects different loads, which...

In non-geostationary orbit satellite networks, the resource is limited and traffic under each in variation due to motion of satellites non-uniform on ground. Generally, uplink communication guaranteed by successful random access (RA) sufficient data transmission (DT) resources for various types. Different types usually have different requirements resources, joint management mixed tries meet needs at same time may improve efficiency. However, existing strategies not given integrative...

Device-free human action recognition (HAR) based on Wi-Fi signals is an essential support in the field of Internet Things and shows bright application prospects. With rapid development deep learning (DL), HAR DL models has become mainstream achieved good performance. However, most these methods are still far from practical application, main challenges include poor cross-environment performance high requirements for sensing devices models. Based this, we propose a cloud-edge collaborative...

Space-aerial-terrestrial integrated networks (SATINs) have gained widespread recognition. Due to the mobility of wireless access points (APs) and user terminals (UTs), handover plays an essential role in ensuring continuity quality communication SATINs. However, existing strategies only consider instantaneous benefits, which makes it difficult maintain link stability with lower frequency. Given that reasonable paths help improve communication, we propose a planning (HP) strategy SATINs,...