Fixed-point simulation results are used for the performance measure of inverting matrices by Cholesky decomposition. The fixed-point Cholesky decomposition algorithm is implemented using a fixed-point reconfigurable processing element. The reconfigurable processing element provides all mathematical operations required by Cholesky decomposition. The fixed-point word length analysis is based on simulations using different condition numbers and different matrix sizes. Simulation results show that 16 bits word length gives sufficient performance for small matrices with low condition number. Larger matrices and higher condition numbers require more dynamic range for a fixedpoint implementation. Keywords—Cholesky Decomposition, Fixed-point, Matrix inversion, Reconfigurable processing.

In this paper multi-user detection techniques, such as Parallel and Serial Interference Cancellations (PIC & SIC), General Minimum Mean Square Error (GMMSE) and polynomial MMSE, for the downlink of a broadband Multi-Carrier Code Division Multiple Access (MCCDMA) system are investigated. The Bit Error Rate (BER) and Frame Error Rate (FER) results are evaluated, and compared with single-user detection (MMSEC, EGC) approaches, as well. The performance evaluation takes into account the system load, channel coding and modulation schemes.

Fixed-point simulation results are used for the performance measure of inverting matrices by Cholesky decomposition. The fixed-point Cholesky decomposition algorithm is implemented using a fixed-point reconfigurable processing element. The reconfigurable processing element provides all mathematical operations required by Cholesky decomposition. The fixed-point word length analysis is based on simulations using different condition numbers and different matrix sizes. Simulation results show that 16 bits word length gives sufficient performance for small matrices with low condition number. Larger matrices and higher condition numbers require more dynamic range for a fixedpoint implementation. Keywords—Cholesky Decomposition, Fixed-point, Matrix inversion, Reconfigurable processing.

The rapid growth of Internet services and increasing interest in portable computing devices creates an even larger demand for high-speed wireless data services in the future. Especially in the downlink, high throughput is needed since the number of downloads of large data files from web sites and servers increases. These requirements needs to be accommodated by future beyond 3rd generation (B3G) cellular systems. Orthogonal frequency division multiplexing (OFDM) and multi carrier code division multiple access (MC-CDMA) are promising candidates for this next generation of mobile radio communication for achieving high data rate transmission. For cellular networks the frequency reuse factor is of high importance since the scarce frequency resource needs to be reused in as many cells as possible. One possible system is to use the same frequency in all cells of the network and have a frequency reuse factor of 1. We therefore investigated the impact of an interfering base station transmitting on the same frequency in an MC-CDMA system. OFDM is investigated as a sub case of MC-CDMA with a spreading factor of one.

ABSTRACT Inthis paper the approach ,and results of the ,project Matrice are presented. Matrice researches MC-CDMA for beyond,3G cellular systems. This contribution includes a description of the baseband ,system and results for Multi User Detection in uplink and downlink,as well as antenna array techniques. Further the radio link layer for Matrice isdescribed,and results are presented. In addition to the simulation,results the implementation ,activities are described and an outlook on the project 4MORE is given, where,the MC-CDMA and multiple antenna solutions from Matrice will be integrated into a System on Chip.