3677results about "Diversity/multi-antenna systems" patented technology

A method for communicating a plurality of data streams between a transmitting device with multiple transmit antennas and a receiving device, is disclosed. The method comprises determining a set of power weightings, efficiently quantizing the power weightings, and providing the set of power weightings the transmitting device. Another aspect of the invention comprises the transmitter implicitly signaling the number of data streams which the receiver should feedback information for through the amount of feedback requested. An additional aspect of the invention is a means of determining the best codebook weights by combining the maximum power and maximum capacity criteria.

Coding techniques for a (e.g., OFDM) communication system capable of transmitting data on a number of “transmission channels” at different information bit rates based on the channels' achieved SNR. A base code is used in combination with common or variable puncturing to achieve different coding rates required by the transmission channels. The data (i.e., information bits) for a data transmission is encoded with the base code, and the coded bits for each channel (or group of channels with the similar transmission capabilities) are punctured to achieve the required coding rate. The coded bits may be interleaved (e.g., to combat fading and remove correlation between coded bits in each modulation symbol) prior to puncturing. The unpunctured coded bits are grouped into non-binary symbols and mapped to modulation symbols (e.g., using Gray mapping). The modulation symbol may be “pre-conditioned” and prior to transmission.

A wireless power transmission unit according to the present invention transmits power wirelessly from a power transmitting section 100 to a power receiving section 200 through a resonant magnetic field. The unit includes: the power transmitting section 100, which resonates at a resonant frequency f0; at least one relay section 300, which can resonate at a frequency that is selected from multiple frequencies including the resonant frequency f0; and a resonance control section 600 that outputs information that specifies a resonance condition to be imposed on the relay section 300 according to the arrangement of the power receiving section 200 and that makes the relay section 300 resonate on the resonance condition that has been specified in accordance with that information.

Methods and apparatus are provided for improved long preamble formats in a multiple antenna communication system having N antennas. According to one aspect of the invention, a preamble having a legacy portion and a high throughput portion is transmitted (or received) on each of the N transmit antennas, wherein the legacy portion comprises a legacy long training field and the high throughput portion comprises at least N high throughput long training fields, wherein the N high throughput long training fields are transmitted in N time slots using an N×N orthogonal matrix. The orthogonal matrix can be, for example, one or more of a Walsh matrix and a Fourier matrix. The N time slots can optionally comprise a single symbol.

A distributed antenna system comprises a base transceiver station, a plurality of distributed antenna units and a signal routing apparatus. The base transceiver station has a plurality of output ports that generate a plurality of downlink signals having overlapping transmit frequencies and containing different communication content. The different communication content is directed toward each of a plurality of mobile units. The base transceiver station also has at least one uplink receive port that receives an uplink signal. The uplink signal includes communication content received from at least one of the mobile units. The plurality of distributed antenna units have coverage areas that are non-overlapping or only partially overlapping. The signal routing apparatus routes the downlink signals to the plurality of distributed antennas such that each of the plurality of downlink signals are transmitted by one or more of the distributed antennas and each distributed antenna only transmits one of the downlink signals.