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This paper deals with the proposal and performance evaluation of a fixed microwave communication (FMC) system that shares the same bandwidth with a wireless personal communication network. In particular, the focus here is on the case of an existing universal mobile telecommunication system (UMTS) network for which an FMC system is considered to provide a wireless connection between a remote base station not having the possibility of a wired connection to the core network and a base station having this possibility (a core network access point). This facility is of special interest in a dense urban environment or whenever a wired connection is prohibitive for service providers due to its implementation cost or lack of frequency spectrum. The mutual interference effects between the FMC systems and the existing UMTSs are investigated by focusing on typical application scenarios. A receiving scheme where interference signals are first detected and then canceled from the other received signals is proposed. The performance of the two interfering systems has been evaluated in terms of bit error rates (BERs) both by means of an analytical approach and computer simulations. The obtained results clearly demonstrate the effectiveness of the proposed method, in particular, by allowing efficient bandwidth sharing between the FMC system and the existing UMTS network. Index Terms--Interference cancellation receivers, spectrum-sharing systems, universal mobile telecommunication system (UMTS), wireless communications.

This paper deals with a variable rate discrete multitone modulation system for broadband power-line communications, based on the bit-loading algorithm proposed by Leke and Cioffi. In the proposed system a suitable least mean square channel estimator is considered, which is based on the insertion of a training sequence (TS). The proposed approach will be compared with the ideal channel estimates, showing its effectiveness. Moreover, different TS lengths will be compared. The system performance, expressed in terms of bit rate and bit-error rate, is derived by simulation with and without estimation errors. The propagation environment has been assumed as a frequency-selective multipath fading channel with additive colored Gaussian noise, according to the in-building networks model. Index Terms--Bit-loading algorithm, broadband power-line communications, discrete multitone modulation, least mean square (LMS) channel estimator.

This paper deals with a multiuser cancellation-detection scheme combined with antenna array for wideband code-division multiple-access (WCDMA) communication systems in which different traffic loads and data rates are considered. This receiver, defined as space-time selective parallel interference-cancellation detector, should be used at the base station of a WCDMA communication system. Asynchronous users and multipath fading phenomena are considered in our analysis. The receiver basic assumption is to divide signals into two different groups according to the received power level. The reliable signals are directly detected and cancelled from the whole received signal at each sensor before making the decision about unreliable signals without any further processing delay. Performance evaluations have been carried out in terms of [P.sub.e](bit error probability) by means of computer simulations. In particular, it is shown that the receiver described in this paper exhibits good behavior and lowers the computational complexity in comparison with previously proposed alternatives. Index Terms--Antenna array, code division multiple access (CDMA), universal mobile telecommunication systems (UMTS).

The ultra dense deployment of small cells is considered a key technology to achieve the requested capacity in future cellular networks. However, the interference pattern becomes more unpredictable and challenging in these networks. Therefore, a suitable trade-off between spectrum spatial reuse and interference level has to be pursued to achieve good performance in terms of provided throughput. This paper proposes a new method to maximize the achievable throughput of an UDN with a suitable level of spatial spectrum reuse. In particular, the focus is on the small cells tier where the available spectrum is divided into sub-bands and each cell can use some of these to communicate with its associated users. The goal is to find the sub-bands allocation among cells that maximizes the system throughput. However, to limit complexity and signaling overhead that could result unaffordable in an UDN, a new metric to approximate the cell throughput to be optimized is defined. Moreover, the newly defined problem is solved using the Gibbs Sampling approach. The method effectiveness is proven by comparing the achieved results with those of the maximization of the effective system throughput and the optimal solution. [ABSTRACT FROM AUTHOR]