7266results about "Transmission control/equalising" patented technology

Exploiting the substantive reciprocity of internode channel responses through dynamic, adaptive modification of receive and transmit weights, enables locally enabled global optimization of a multipoint, wireless electromagnetic communications network of communication nodes. Each diversity-channel-capable node uses computationally efficient exploitation of pilot tone data and diversity-adaptive signal processing of the weightings and the signal to further convey optimization and channel information which promote local and thereby network-global efficiency. The preferred embodiment performs complex digital signal manipulation that includes a linear combining and linear distribution of the transmit and receive weights, the generation of piloting signals containing origination and destination node information, as well as interference-avoiding pseudorandom delay timing, and both symbol and multitone encoding, to gain the benefit of substantive orthogonality at the physical level without requiring actual substantive orthogonality at the physical level.

A system and method are described for compensating for frequency and phase offsets in a multiple antenna system (MAS) with multi-user (MU) transmissions (“MU-MAS”). For example, a method according to one embodiment of the invention comprises: transmitting a training signal from each antenna of a base station to one or each of a plurality of wireless client devices, one or each of the client devices analyzing each training signal to generate frequency offset compensation data, and receiving the frequency offset compensation data at the base station; computing MU-MAS precoder weights based on the frequency offset compensation data to pre-cancel the frequency offset at the transmitter; precoding training signal using the MU-MAS precoder weights to generate precoded training signals for each antenna of the base station; transmitting the precoded training signal from each antenna of a base station to each of a plurality of wireless client devices, each of the client devices analyzing each training signal to generate channel characterization data, and receiving the channel characterization data at the base station; computing a plurality of MU-MAS precoder weights based on the channel characterization data, the MU-MAS precoder weights calculated to pre-cancel frequency and phase offset and / or inter-user interference; precoding data using the MU-MAS precoder weights to generate precoded data signals for each antenna of the base station; and transmitting the precoded data signals through each antenna of the base station to each respective client device.

In some aspects, each cell in the communications system can be designed to operate in accordance with a set of back-off factors that identify the reductions in peak transmit power levels for the channels associated with the back-off factors. The back-off factors are defined to provide the required power to a large percentage of the users while reducing the amount of interference. In some other aspects, the cells operate using an adaptive reuse scheme that allows the cells to efficiently allocate and reallocate the system resources to reflect changes in the system. A reuse scheme is initially defined and resources are allocated to the cells. During operation, changes in the operating conditions of the system are detected and the reuse scheme is redefined as necessary based on the detected changes. In yet other aspects, techniques are provided to efficiency schedule data transmissions and to assign channels to users.