This paper presents the design patterns and architecture of a testbed for the evaluation of quality of service (QoS) provisioning in WCDMA (wideband code division multiple access) based third generation wireless networks. The testbed allows for the evaluation of QoS adaptation techniques that supercedes to the traditional power control in the radio resource manager (RRM). It handles classes of service defined for the Universal Mobile Telecommunication System (UMTS), as well as mobility and handoffs.

Quality of service aware power control (QaPC) mechanisms that supersede to the traditional closed loop power control in wideband code division multiple access (WCDMA) type of networks, such as the Universal Mobile Telecommunication System (UMTS), provide significant advantages over blind channel estimation mechanisms. These mechanisms integrate specific QoS requirements of users in power control decision yielding optimal use of resources available at the base. Similarly QoS aware prioritization of handoffs (QaHO) that leverage user QoS profile can also yield significant improvements over blind prioritization. This paper presents two such QaPC and QaHO mechanisms which are based on the class of service, the bitrate, and the service degradation descriptor (SDD) [O. Lataoui et al., 2000] as enabling QoS parameters. The performance of our combined QaPC and QaHO mechanisms obtained using the test bed described in [A.Y. Elbatji et al., Sept. 2003], under a variety of load and traffic scenarios, and admission strategies is also presented. The results show that, when measured against blind mechanisms, the combined QaPC and QaHO significantly improves contract upholding of premium service mobile users, as well as improve resource utilization by more than 22% while improving handoffs failures by 12 %.

This correspondence presents a general approach to upper bounding coded system performance over quasistatic fading channels (QSFC). This approach has the advantage of yielding a closed-form upper bound that converge for all signal-to-noise ratios (SNRs). The proposed approach is used to upper-bound the performance of space-time trellis codes (STTC) over QSFCs. The resulting upper bounds for STTCs are better adapted to the QSFC and present an improvement over worst case pairwise error probability (PEP) analysis used so far. In its second part, this correspondence investigates several ways to reduce the complexity of computing the distance spectrum of STTCs. The combined result obtained from using the new upper bounds and the computed distance spectra are shown to be close to simulated performance for all SNRs.

This paper proposes effective ways to reduce the complexity of computing the distance spectrum of space-time trellis codes. First the notion of Voronoi neighborhood is extended to space-time trellis codes. Next, only simple error events are used, then a stack algorithm is used to further reduce complexity. The obtained reduced spectra are then used in conjunction with some previously proposed upper bounds to predict the performance of some published codes over quasi-static fading channels. Of interest are published space-time codes for which only tentative performance characterization has been proposed so far. The numerical results show that indeed the performance of these codes only depends on their distance spectrum and that remarkably tight bounds can be obtained.

This paper investigates several upper bounds and their validity for a particular space-time concatenated coding scheme. The system under study is a serial concatenation of a trellis outer code to provide coding gain followed by a space-time block code to insure diversity. Of interest is the performance of the coding scheme over a quasi-static fading channel (QSFC). It is shown in this paper how the classical union bound is divergent for the QSFC and this makes it unsuitable for studying codes and building design criteria. A different upper bound based on Berlekamp's tangential bound (TB) is derived and its suitability for the purpose of analyzing this concatenation scheme is explored. Finally a new upper bound is derived which results in a more stable alternative. The result is a remarkably simple yet very reliable upper bound for space-time coded systems. Simulation results from an example scheme are provided and show that the new bound does indeed give a useful upper bound on the true system performance.