In recent years, advances in immersive multimedia technologies, such as extended reality (XR) technologies, have led to more realistic and user-friendly devices. However, these devices are often bulky and uncomfortable, still requiring tether connectivity for demanding applications. The deployment of the fifth generation of telecommunications technologies (5G) has set the basis for XR offloading solutions with the goal of enabling lighter and fully wearable XR devices. In this paper, we present a traffic dataset for two demanding XR offloading scenarios that substantially extend those available in the current state of the art, captured using a fully developed end-to-end XR offloading solution. We also propose a set of accurate traffic models for the proposed scenarios based on the captured data, accompanied by a simple and consistent method to generate synthetic data from the fitted models. Finally, using an open-source 5G radio access network (RAN) emulator, we validate the models both at the application and resource allocation layers. Overall, this work aims to provide a valuable contribution to the field with data and tools for designing, testing, improving, and extending XR offloading solutions in academia and industry.

The upcoming IEEE 802.11be standard aims to provide extremely high bitrates to support next generation use cases. Among the proposed features, multi-link operation (MLO) is probably the one contributing most towards this goal. MLO enables new types of devices, i.e., multi-link devices (MLDs), to transmit simultaneously over multiple frequency bands to achieve massive bitrates (reaching 40 Gbps) and, consequently, lower latency. However, the coexistence of MLDs with legacy devices in existing and future wireless local area network (WLAN) deployments has not yet been explicitly investigated. In this work, we investigate different band management policies over a three-band densely populated WLAN, allowing MLDs to use one or more bands for the access procedure and data transfer. We evaluate, via extensive simulations, the access delay of the devices and the network throughput with respect to the ratio of legacy devices and MLDs. We show that by using different band allocation policies for MLDs, several trade-offs regarding throughput and access delay arise that need careful consideration to avoid performance degradation.

This paper proposes a successive coordinated power allocation (SCPA) scheme for orthogonal frequency division multiple access (OFDMA) systems based on the water-filling algorithm. The model assumes two transmitters belonging to heterogeneous cells, i.e. a macro cell and a micro/pico cell with predefined different power capabilities that cover a common geographical area over a channel that includes path loss and shadowing. The main idea is the reduction of the computation complexity and the minimization of information exchange between the two transmitters while preserving similar performance with the optimal cooperative power allocation (OCPA) joint transmission algorithm, recently proposed in the literature. The algorithms are evaluated via extensive Monte-Carlo simulations. The results show that the proposed algorithm provides similar sum rate than OCPA and presents a higher mean number of serving mobile units while reducing, at the same time, the complexity by roughly to orders of magnitude.

This paper proposes and analyzes a binary information transmission system with complex orthogonal coding based on the use of amicable Hadamard matrices. The proposed configuration is analyzed over Rayleigh fading channels with coherent maximum aposteriori probability (MAP) vector detection. The performance of the system is evaluated in terms of the bit error probability (BEP) with simulation and/or mathematical analysis and presents great enhancement compared to standard binary phase shift keying (BPSK) modulation under identical information rate and mean power constraints. The system performance is enhanced by increasing the size of Hadamard matrices at a cost of complexity increase due to MAP detection. Comparison with real Hadamard matrices coded configurations, recently proposed, favors the proposed system with significant difference.

We introduce the channel quality estimation index (CQEI) as an alternative improved long-term performance criterion for wireless communications systems operating over fading channels. CQEI is simple to evaluate, since it depends on the channel statistics which vary much more slowly than the channel state itself, and thus can be obtained at the initialization state using a long training sequence and afterwards continuously improved during the whole communication period. Considering generalized fading channels (Nakagami-m, Nakagami-n, Nakagami-q) and a variety of modulations, we show that CQEI assesses the average error performance of a communication system more efficiently, compared to other long- term performance criteria such as the average signal to noise ratio (ASNR) and the amount of fading (AoF). As an application, we utilize CQEI to present a new class of equal gain combining (EGC) receivers operating over non-identical independent fading channels, called selection-EGC (S-EGC). This kind of receivers reduces or eliminates the combining loss by rejecting the weak branches that contribute more to increasing the noise than the signal during the combining stage. S-EGC could be efficiently applied in the emerging broadband communication systems (e.g., ultra-wideband), where the number of diversity paths can be considerably large due to the strong multipath effects. Numerical results show that the new proposed selection-EGC (S-EGC) receiver outperforms the classical one, when fading with non- identically distributed diversity branches is assumed.

In this paper, we derive an analytical framework for the performance evaluation of an M-ary orthogonal scheme based on differential encoding/decoding of the Walsh/Hadamard chips prior/after spreading. This technique makes feasible nonpilot-assisted detection over fast fading environments such as the land mobile satellite (LMS) channel. Our results show that differential M-ary orthogonal signaling presents very good performance at Doppler frequency shifts much higher than the symbol rate. Amplitude statistics are considered to be Rayleigh, but may be easily extended to more general models based on the analytical derivation presented.

This paper presents a DS/CDMA system based on M-ary orthogonal signaling and Reed-Solomon (RS) coding for voice and data cellular communications. The proposed system is analysed under Rician or Rayleigh fading, either frequency selective or nonselective depending on the transmission bandwidth. Lognormal shadowing and a two-slope path loss channel model are considered. Numerical together with simulation results and comparison with previous work verify that the system under consideration consists a strong candidate for cellular communications.

In this paper a direct sequence spread-spectrum multiple access communication system is studied for a frequency selective mobile radio channel. The reverse link (mobile to base station) is analysed, assuming Rayleigh fading channel and K asynchronous users, with M orthogonal sequences per user. The analysis is based on the consideration of the quadrature components of the signal and noise. The proposed receiver is a modified RAKE receiver that improves the performance of the system at medium signal to noise ratios (SNR), giving the possibility of applying this system in a high noise cellular mobile radio environment.