Correlation properties of large scale fading based on Indoor measurements

in IEEE Wireless Communications and Networking Conference (2007)

Statistical channel models are attractive for their simplicity but sometimes lack in precision. In to improve modelling accuracy, statistical model parameters, which are dependent on the environment, are ... [more ▼]

Statistical channel models are attractive for their simplicity but sometimes lack in precision. In to improve modelling accuracy, statistical model parameters, which are dependent on the environment, are extended to include spatial and temporal correlation. In outdoor scenarios these parameters are assumed constant over large areas of several wavelengths hence the name large scale parameters. This paper studies the large scale fading (LSF) and the applicability of bringing this previously used outdoor variable to the indoor case. The impacts of the model of the LSF on the outdoor system-performance have been studied and several relevant models have been proposed for outdoor cases. We present the intra-site autocorrelation as well as the inter-site cross correlation of the LSF for an indoor channel. The results are based on two separate measurement campaigns conducted at KTH, Stockholm and TUI, Ilmenau, using a single mobile station (MS) and multiple base stations (BSs) to investigate such models. We observe that the areas under which the LSF could be assumed constant are, in indoor scenarios, so small that it can be assumed independent from one local area to another. Furthermore, we find results that point towards the existence of inter-site correlation in some specific scenarios. [less ▲]

Full Diversity Detection in MIMO Systems with a Fixed-Complexity Sphere Decoder

in Proceedings IEEE International Conference on Acoustics, Speech, and Signal Processing (2007)

System Evaluation of Optimal Downlink Beamforming with Congestion Control in Wireless Communication

in IEEE Transactions on Wireless Communications (2006), 5(4), 743751

Interference Robustness Aspects of Space-Time Block Code-Based Transmit Diversity

in IEEE Transactions on Signal Processing (2005), 53(4), 12991309

Array Interpolation and DOA MSE Reduction

in IEEE Transactions on Signal Processing (2005), 53(12), 44644471

MIMO Channel Capacity and Modeling Issues on a Measured Indoor Radio Channel at 5.8 GHz

in IEEE Transactions on Wireless Communications (2005), 4(3), 895903

When will smart antennas be ready for the market? Part I

in EURASIP Journal on Wireless Communications and Networking (2005), 22(2), 87-92

Array Interpolation and Bias Reduction

in IEEE Transactions on Signal Processing (2004), 52(10), 27112720

A QoS-aware Proportional Fair Scheduler for Opportunistic OFDM

in Proceedings IEEE Vehicular Technology Conference, Fall (2004)

Power Allocation and Bit Loading for Spatial Multiplexing in MIMO Systems

in Proceedings IEEE International Conference on Acoustics, Speech, and Signal Processing (2003)

The power assignment problem is important for Multiple-Input-Multiple-Output (MIMO) systems to achieve high capacity. Although this problem is solved by well-known water filling algorithms, this does not ... [more ▼]

The power assignment problem is important for Multiple-Input-Multiple-Output (MIMO) systems to achieve high capacity. Although this problem is solved by well-known water filling algorithms, this does not provide an optimal solution if the system is constrained to a fixed raw bit error rate threshold and to discrete modulation s. In this work an approximate approach, called QoS based WF, is proposed to solve the power assignment problem with such constrains. It is shown to outperform quantization of the conventional water filling solution and a well known bit loading algorithm (Chow's algorithm) used in the Digital Subscriber Lines (DSL). [less ▲]