Abstract:
Location of a portable device with a transmitter, such as a wireless transmit/receive unit (WTRU) in a cellular telecommunications network, is obtained by a primary network augmented by data obtained from a diverse network. In a particular configuration, changes of the indication of the location of the portable device are used to update positional information, such as positional information obtained from a GPS receiver.
Abstract:
A wireless communications system employs code-division multiple access information transmission techniques where the uplink and downlink transmission bandwidths are unequal. The higher bandwidth is an integer multiple of the lower bandwidth. The present system requires a base station and a subscriber unit to have two pseudo-random code generators which can be clocked separately. Alignment of the uplink and downlink pseudo-random spreading codes is achieved by truncating the code sequence for the lower speed link at the conclusion of a complete code sequence for the higher speed link.
Abstract:
A method and apparatus for radio resources control in a multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) communication system are disclosed. Channel metric is calculated for each of a plurality of transmit antennas. Sub-carriers are allocated to each transmit antenna in accordance with the channel metric of each transmit antenna. Signals are transmitted using the allocated sub-carriers at each antenna. Adaptive modulation and coding and transmit power control of each sub-carrier may be further implemented in accordance with the channel metric. Power control may be implemented per antenna basis or per sub-carrier basis. In performing power control, a subset of transmit antennas may be selected and waterpouring may be applied only to the selected antennas. Waterpouring may be based on SNR instead of channel response.
Abstract:
A method and apparatus for combining space-frequency block coding (SFBC), spatial multiplexing (SM) and beamforming in a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system. The system includes a transmitter with a plurality of transmit antennas and a receiver with a plurality of receive antennas. The transmitter generates at least one data stream and a plurality of spatial streams. The number of generated spatial streams is based on the number of the transmit antennas and the number of the receive antennas. The transmitter determines a transmission scheme in accordance with at least one of SFBC, SM and beam forming. The transmitter transmits data in the data stream to the receiver based on the selected transmission scheme.
Abstract:
A wireless communications system employs code-division multiple access information transmission techniques where the uplink and downlink transmission bandwidths are unequal. The higher bandwidth is an integer multiple of the lower bandwidth. The present system requires a base station and a subscriber unit to have two pseudo-random code generators which can be clocked separately. Alignment of the uplink and downlink pseudo-random spreading codes is achieved by truncating the code sequence for the lower speed link at the conclusion of a complete code sequence for the higher speed link.
Abstract:
Data is to be transmitted in a code division multiple access communication system. A channel response is provided as a channel response matrix H approximating a channel that the data will experience after transmission. The data is spread and the spread data is processed with the channel response matrix H. The spread and processed data is transmitted. The data is received and recovered from the transmitted spread and processed data.
Abstract:
A transmitting station receives a transmit power command and a reference signal. The transmit power command indicates an increase or decrease in transmission power for the transmitting station. A received power level of the reference signal is measured and the measured reference signal received power level is compared to a transmit power level of the reference signal to produce a pathloss estimate of the reference signal. A size of a change in transmit power level is determined using the pathloss estimate. A transmission power level of the transmitting station is adjusted in response to the transmit power command in an amount of the determined change in size. A communication is transmitted at the adjusted transmission power level.
Abstract:
A wireless transmit/receive unit (WTRU) has multiple receivers with an interface to combine received signals to provided enhanced reception. A control unit selectively controls the powering of the receivers to limit power consumption based on selected parameters.
Abstract:
A digital baseband (DBB) receiver for receiving and processing a wireless communication signal. The DBB receiver includes at least one low noise amplifier (LNA), at least one demodulator, a direct current (DC) discharge circuit and an LNA control circuit. The LNA selectively amplifies the communication signal. The demodulator outputs analog real and imaginary signal components on real and imaginary signal paths, respectively, in response to receiving the communication signal from the LNA. The DC discharge circuit selectively discharges DC accumulating on at least one of the real and imaginary signal paths. The LNA control circuit turns the LNA on or off.
Abstract:
A receiver employing CDMA techniques estimates background noise based on a periodically updated code. The transmitted signal includes a periodically updated code of a predetermined type and wherein the received signal has CW interference in addition to the transmitted signal. The decision circuit determines if a value representing the likelihood of detection of the code exceeds a predetermined threshold. In the case of a pilot signal not being detected within a predetermined time period which corresponds to code update period, the background noise estimator obtains a new background estimation.