Oxidized (non)-regenerated cellulose affects fundamental cellular processes of wound healing.

In this study we investigated how hemostats such as oxidized regenerated cellulose (ORC, TABOTAMP) and oxidized non-regenerated cellulose (ONRC, RESORBA CELL) influence local cellular behavior and contraction of the extracellular matrix (ECM). Human stromal fibroblasts were inoculated in vitro with ORC and ONRC. Cell proliferation was assayed over time, and migration was evaluated by Live Cell imaging microscopy. Fibroblasts grown in collagen-gels were treated with ORC or ONRC, and ECM contraction was measured utilizing a contraction assay. An absolute pH decline was observed with both ORC and ONRC after 1 hour. Mean daily cell proliferation, migration and matrix contraction were more strongly inhibited by ONRC when compared with ORC (p < 0.05). When control media was pH-lowered to match the lower pH values typically seen with ORC and ONRC, significant differences in cell proliferation and migration were still observed between ONRC and ORC (p < 0.05). However, in these pH conditions, inhibition of matrix contraction was only significant for ONRC (p < 0.05). We find that ORC and ONRC inhibit fibroblast proliferation, migration and matrix contraction, and stronger inhibition of these essential cellular processes of wound healing were observed for ONRC when compared with ORC. These results will require further validation in future in vivo experiments to clarify the clinical implications for hemostat use in post-surgical wound healing

Fair OFDMA scheduling algorithm using iterative local search with k-opt-switches

An iterative algorithm for the multiuser fair scheduling problem of adaptive OFDMA systems is presented. It uses iterative local search with k-opt switches in the combinatorial solution space. The algorithm can be used with different scheduling criteria like proportional fairness and maxmin fairness, both for constant and adaptive allocation of power to subcarriers/resource blocks. The algorithm is applied to a simplified model of 3GPP LTE and its properties are simulatively investigated in the constant power and the adaptive power case

On predicting convergence of iterative MIMO detection-decoding with concatenated codes

We evaluate the applicability of methods from stochastic decoding analysis to convergence prediction of iterative multiple-input-multiple-output (MIMO) detection decoding. The one-parametric conditional Gaussian log-likelihood ratio (LLR) distribution model, which underlies EXtrinsic Information Transfer (EXIT) charts, is not adequate for some practically relevant scenarios such as fading MIMO channels. A more recent two-parametric Gaussian model, which better fits arbitrary distributions, can be combined with an offset compensation to allow for a chart-based prediction of the convergence of iterative receiver processing in these cases

A novel low-complexity algorithm for linear MMSE MIMO receivers

Computation of MIMO equalization matrices is a critical and computationally intensive part of today's and future MIMO-OFDM receivers. We present a novel algorithm for computation of the MMSE MIMO equalizer matrix which, compared with the state of art, reduces the number of multiplications by 10% while also featuring innermost loops of a fixed length, allowing for unrolling and easy implementation in custom hardware or on vector processors

On hardware implementation of multiuser multiplexing for SC-FDMA

A simple algorithmic scheme is proposed which calculates multiple variable-length FFTs/IFFTs at once by a single fixed-length one. The algorithm exploits the fact that the transform of a periodic signal is a line spectrum, the linearity property of FFT/IFFT and the shift theorem. The overall algorithm complexity is higher than calculating separate variable- length transforms, but the ease of implementation makes the scheme well-suited for FPGA based rapid prototyping systems. Because in SC-FDMA systems multiple variable-length transforms are needed for different users, the algorithm can be used to implement multiuser multiplexing. The scheme can be applied to DFT/IDFT as well as FFT/IFFT implementations

Joint model for fine synchronization and adaptive LMMSE channel estimation in uplink OFDMA

In this paper parametric tracking of channel and synchronization errors for an adaptive multi-dimensional channel estimator for uplink Orthogonal Frequency Division Multiplex Access (OFDMA) communication systems is proposed. The estimator consists of a two-dimensional LMMSE filter. In real world scenarios, channel estimation should work not only in a wide range of terminal velocities and delay spread but it is also confronted with time and frequency synchronization errors affecting the channel estimation and thus limits the performance of both the coherent receiver and overall OFDMA system. We jointly track channel statistics and synchronization errors so that LMMSE filter coefficients closely reflect the current statistics of the channel. Through simulations it is verified that the proposed channel estimator outperforms the robust LMMSE estimator in the presence of synchronization errors and varying channel conditions

12 × 12 MIMO-OFDM realtime implementation for 3GPP LTE+ on a cell processor

We present a realtime implementation of the time-critical core functions for 12 × 12 MIMO-OFDM (12 data streams) with LTE parameters on a cell broadband engine processor. An MMSE equalizer matrix update interval of 1 ms (high mobility) is achieved with less than 50% CPU utilization. Concurrent bidirectional processing (precoding and postprocessing) is shown to be feasible with this update rate

Verfahren zum Steuern einer Relaisstation in einem Mobilfunknetzwerk

DE 102008009087 A1 UPAB: 20090928 NOVELTY - The method involves receiving bandwidth requirements from terminals (150,160,170) by a broadcasting station (140). An aggregated bandwidth requirement is determined by the broadcasting station. The aggregated bandwidth requirement is sent from the broadcasting station to base stations (110,120). An aggregated bandwidth authorization is received by the broadcasting station from the base stations. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a computer program product with a program code for executing a controlling method of a broadcasting station of a portable radio network; and (2) a system consisting of two broadcasting stations. USE - Method for controlling a broadcasting station of a portable radio network (Claimed). ADVANTAGE - The aggregated bandwidth requirement is determined by the broadcasting station and the aggregated bandwidth requirement is sent from the broadcasting station to base stations, and hence enables to receive and send the data traffic between the base station and one or more terminals wirelessly