3GPP LTE is the evolution of UMTS which will make possible to deliver high quality multimedia services with an improved user experience. Since Radio Resource Management (RRM) has been recognized as a key point to successfully accomplish this target, the performance evaluation of a multi-cell resource allocation scheme applied to LTE downlink (DL) is presented in this paper. A semi-distributed RRM framework is discussed and evaluated from a system level viewpoint. Detailed link level simulations have also been carried out to properly back up the results.

3GPP LTE is the evolution of UMTS which will make possible to deliver next generation high quality multimedia services according to the users' expectations. The flexibility of the downlink OFDM radio interface with Adaptive Modulation and Coding (AMC), MIMO and H-ARQ plays a crucial role in achieving the low latency and high spectral efficiency promised by the new radio access standard. This paper presents a LTE DL link level simulator whose main purpose is to generate suitable look-up tables to interface with a system level simulator. In this context, the Exponential Effective SIR (EESIR) metric is a link abstraction model that is used to properly characterize multistate channels. The reference BLER curves in AWGN channel and the parameters of the EESIR model are given for the complete list of CQI's specified for LTE DL. The obtained results also include curves of mean link level throughput for different AMC formats and MIMO configurations.

Tuning parallel applications requires the use of effective tools for detecting performance bottlenecks. Along a parallel program execution, many individual situations of performance degradation may arise. We believe that an exhaustive and time-aware tracing at a fine-grain level is essential to capture this kind of situations. This paper presents a tracing mechanism based on dynamic code interposition, and compares it with the usual compiler-directed code injection. Dynamic code interposition adds monitoring code at run-time to unmodified binaries and shared libraries, making it suitable for environments in which the compiler or the available tools do not offer instrumentation facilities. Static injection and dynamic interposition techniques are used to collect detailed traces that feed an analysis tool. Both environments meet the accuracy and performance goals required to profile and analyze parallel applications and runtime libraries.