Abstract: A beamforming method and a beamforming apparatus for directional signal transmission are provided, wherein a multiple antenna beamformer is configured to conduct a data transmission to a beamformee.

Abstract: In this application, an algorithm for decoding multiple input-multiple output (MIMO) transmission for communication systems is provided; the algorithm combines sphere decoding (SD) and zero forcing (ZF) techniques to provide near optimal low complexity and high performance constant time modified sphere decoding algorithm; the algorithm was designed especially for large number of transmit antennas, that allows efficient implementation in hardware—this is done by limiting the number of overall SD iterations; moreover, matrices with high condition number are more likely to undergo SD.

Abstract: A communications system comprising at least one Base Station BS, one or more Satellites and Mobile Stations MS connected therebetween, and wherein the mobile station includes means to calculate Doppler frequency shifts. In a preferred embodiment, the mobile station includes means to measure clock mismatch frequency.

Abstract: In this application, an algorithm for decoding multiple input-multiple output (MIMO) transmission for communication systems is provided; the algorithm combines sphere decoding (SD) and zero forcing (ZF) techniques to provide near optimal low complexity and high performance constant time modified sphere decoding algorithm; this algorithm was designed especially for large number of transmit antennas, that allows efficient implementation in hardware—this is done by limiting the number of overall SD iterations; moreover, we make sure that matrices with high condition number are more likely to undergo SD.

Abstract: Selecting an optimal ECINR mode in a digital communication system, by constructing an offline relevant modes database having a list of transmission-reception methods for possible MIMO configurations, and mobility characterization, gathering online channel state and capabilities information, retrieving parameters from the relevant modes database, based on the gathered data/information for creating a concurrent list, excluding some MIMO modes off the list, for which the available channel matrix is insufficient, the modes left at the end of this step being “currently relevant modes’, calculating post processing per tome physical CINR (PCINR) for each of the currently relevant modes found, calculating ECINR for each of the currently relevant modes using the PCINR, choosing the optimal MIMO mode and MCS combination, which is the parameters' combination with highest throughput, which provide the best ECINR under QoS requirements.

Abstract: A method for computing ECINR in communication systems, by calculating or measuring instantaneously CINR (yi) or per-tone CINR value for each channel and/or bandwidth and/or signal of interest, selecting ? and ? parameters according to MCS and/or FEC block size used, calculating ECINR by using the CINR ((yi) or per-tone CINR values and the ? and ? parameters with a generalized EESM formula, and providing a communication system with the updated ?eff which is the ECINR value.

Abstract: A method for grouping terminal devices in a wireless communication network containing a base-station, wherein each terminal reports to the base-station the level of signal received the terminal when the base-station transmits to another terminal or terminals. The base-station then selects from the plurality of the terminals, groups of terminals indicating low signal measurements for data transmissions sent to other group members of the group.

Abstract: A method for maintaining satellite diversity for a WiMAX system comprising: A. Dividing a set of UTs or users into subsets wherein each set is devised such that the maximal time delay between its members does not exceed the GI length; B. One or more BS's or satellites acquires information or estimation regarding relative delay between subsets; C. A different FFT is performed for each subset, wherein each has its own time alignment; D. Interference reduction means are implemented in the frequency domain between subsets.

Abstract: A communications system comprising at least one Base Station BS, one or more Satellites and Mobile Stations MS connected therebetween, and wherein the mobile station includes means to calculate Doppler frequency shifts. In a preferred embodiment, the mobile station includes means to measure clock mismatch frequency.

Abstract: A method for calculating channel quality in a multi-stream communication system, by calculating channel quality for each selectable stream of the multi-stream communication system, based on estimation of at lest one set of error vectors.