Abstract:
Method and apparatus for transfer of signals from multiple antennas down to baseband over a common radio frequency (RF) chain. Antenna selection having greater flexibility and applicability to both uplink and downlink wherein priority is given to the antenna receiving a better quality signal. Measurements are taken during each time slot to determine the weighting to be given to the antenna with the better quality signal. Techniques and apparatus are provided to take measurements over a range of intervals from time slots to single symbols, for example, to select the best signal the techniques described herein may be used individual, and in some cases are combined to receive additional benefits in efficiency.
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 method and apparatus for providing a wireless transmit/receive unit (WTRU) with access to at least one peripheral device, and/or at least one peripheral device associated with an available auxiliary device. The current peripheral device requirements of the WTRU are determined. The radio frequency (RF) environment of the WTRU is scanned to determine if there are any available wireless peripheral devices or wireless auxiliary devices proximate to the WTRU. A determination is also made as to whether there is a wired peripheral device or a wired auxiliary device available. A list of currently available peripheral devices is compiled by scanning at least one peripheral device registry associated with at least one of a wireless auxiliary device and a wired auxiliary device. The list is presented on the WTRU's display and a user selects at least one of the available peripheral devices from the list.
Abstract:
A transmitter (200) splits a user-data stream into a plurality of sub-streams (201 1 -201 n ). The transmitter (200) then adaptively select a modulation scheme and coding rate for each of the sub-streams based on current channel conditions. Next, a plurality of sub-carrier (211 1 -211 n ) are modulated and encoded with the sub-stream data according to the selected modulation schemes and coding rates. The modulated sub-carriers are each allocated to one or more transmit antennas (220 1 -221 n ) for transmission. Prior to transmission, a transmission power for each of the sub-carriers is adjusted based on the channel conditions.
Abstract:
A method and system for utilizing smart antenna in transmission of messages between nodes are disclosed. A wireless communication system includes a plurality of nodes, and each node is capable of being connected to each other node. At least a portion of the nodes are provided with a smart antenna configured to generate a plurality of directional beams. Each node maintains a list of other nodes and beam configuration information to be used in transmission of messages to other nodes. When a source node is required to transmit to a target node, the source node retrieves the beam configuration information and transmits with a directional beam directed to the target node.
Abstract:
A transmission is simultaneously provided on multiple mesh networks. Retransmission between two nodes may be performed for the same communication along multiple networks in a mesh topography for the multiple networks. This permits communication to be effected in a mesh topography where one or all systems would not be able to provide a complete network connection within any given system.
Abstract:
A method and system for mapping quality of service requirements between various types of wireless communication systems is disclosed. The mapping is performed according to the type of systems across which the mapping is being provided.
Abstract:
A multiple access, spread-spectrum communication system processes a plurality of information signals received by a Radio Carrier Station (RCS) over telecommunication lines for simultaneous transmission over a radio frequency (RF) channel as a code-division-multiplexed (CDM) signal to a group of Subscriber Units (SUs). The RCS receives a call request signal that corresponds to a telecommunication line information signal, and a user identification signal that identifies a user to receive the call. The RCS includes a plurality of Code Division Multiple Access (CDMA) modems, one of which provides a global pilot code signal. The modems provide message code signals synchronized to the global pilot signal. Each modem combines an information signal with a message code signal to provide a CDM processed signal. The RCS includes a system channel controller coupled to receive a remote call. An RF transmitter is connected to all of the modems to combine the CDM processed signals with the global pilot code signal to generate a CDM signal. The RF transmitter also modulates a carrier signal with the CDM signal and transmits the modulated carrier signal through an RF communication channel to the SUs. Each SU includes a CDMA modem which is also synchronized to the global pilot signal. The CDMA modem despreads the CDM signal and provides a despread information signal to the user. The system includes a closed loop power control system for maintaining a minimum system transmit power level for the RCS and the SUs, and system capacity management for maintaining a maximum number of active SUs for improved system performance.
Abstract:
An automatic power control (APC) system for a spread-spectrum communications system includes an automatic forward power control (AFPC) system, and an automatic reverse power control (ARPC) system. In the AFPC, each subscriber unit (SU) measures a forward signal-to-noise ratio of a respective forward channel information signal to generate a respective forward channel error signal which includes a measure of the uncorrelated noise in the channel and a measure of the error between the respective forward signal-to-noise ration and a pre determined signal-to-noise value. A control signal generated from the respective forward channel error signal is transmitted as part of a respective reverse channel information signal. A base unit includes AFPC receivers which receive respective reverse channel information signals and extract the forward channel error signals therefrom to adjust the power levels of the respective forward spread-spectrum signals. In the ARPC system, each base measures a reverse signal-to-noise ratio of each of the respective reverse channel information signals and generates a respective reverse channel error signal which includes a measure of the uncorrelated noise in the channel and a measure of the error between the respective reverse signal-to-noise ratio and a pre determined signal-to-noise value. The base unit transmits a control signal generated from the respective reverse channel error signal as a part of a respective forward channel information signal. Each SU includes an ARPC receiver which receives the forward channel information signal and extracts the respective reverse error signal to adjust the reverse transmit power level of the respective reverse spread-spectrum signal.
Abstract:
A method for performing cell search in an orthogonal frequency division multiple access (OFDMA) based cellular communication network in which a primary synchronization channel (P-SCH), and optionally a secondary synchronization channel (S-SCH), carries cell search information. A downlink signal is received containing P-SCH symbols. The P-SCH symbols are processed to obtain an initial detection of frame timing, orthogonal frequency division multiplexing (OFDM) symbol timing, a cell identifier (ID), a frequency offset, and a cell transmission bandwidth. Optionally, an OFDM symbol timing self-check and error correction is then performed.