Abstract: A method for determining the validity of a most significant path in a wireless communication system wherein data is transmitted in frame units in a multipath environment begins by accumulating a correlated data sequence N times, each time at a frame offset apart from the previous time. A preliminary noise estimate (PNE) is calculated as an average of the accumulated data values. A preliminary noise threshold (PNT) is calculated according to the equation C1×PNE. A final noise estimate (FNE) is calculated as the average of accumulated data values below the PNT. A final noise threshold (FNT) is calculated according to the equation C2×FNE. The validity of the most significant path is determined if the most significant path value is greater than the FNT.

Abstract: A method and apparatus for handling a control channel for carrier aggregation in wireless communications. The method includes determining which component carrier to listen to, detecting the downlink control channel, processing mapping information related to downlink and uplink transmissions and operating discontinuous reception with respect to carrier aggregation. The method also includes detecting a component carrier, determining the component carrier type and locating the anchor component carrier, if necessary, where the anchor component carrier carries the carrier aggregation information.

Abstract: A power control scheme for an enhanced Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA) physical uplink shared channel (PUSCH) is disclosed. In a first embodiment, when an uplink grant is configured for accumulation commands, the wireless transmit/receive unit (WTRU) combines the accumulation commands received in both the scheduling grant and the transmit power control physical downlink control channel. In a second embodiment, when an uplink grant is configured for absolute commands, the WTRU resets the accumulation control function immediately after receiving each absolute transmit power control command and then combines the absolute power control with the accumulation power control.

Abstract: A power control scheme for an enhanced Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA) physical uplink shared channel (PUSCH) is disclosed. In a first embodiment, when an uplink grant is configured for accumulation commands, the wireless transmit/receive unit (WTRU) combines the accumulation commands received in both the scheduling grant and the transmit power control physical downlink control channel. In a second embodiment, when an uplink grant is configured for absolute commands, the WTRU resets the accumulation control function immediately after receiving each absolute transmit power control command and then combines the absolute power control with the accumulation power control.

Abstract: A method and apparatus for handling a control channel for carrier aggregation in wireless communications. The method includes determining which component carrier to listen to, detecting the downlink control channel, processing mapping information related to downlink and uplink transmissions and operating discontinuous reception with respect to carrier aggregation. The method also includes detecting a component carrier, determining the component carrier type and locating the anchor component carrier, if necessary, where the anchor component carrier carries the carrier aggregation information.

Abstract: A method and an apparatus for performing multiple-input multiple-output (MIMO) wireless communications are disclosed. A Node-B may receive an index to a pre-coding matrix in a single user MIMO (SU-MIMO) pre-coding codebook from wireless transmit/receive units (WTRUs) and adaptively perform one of SU-MIMO or multi-user MIMO (MU-MIMO) based on a predetermined criterion. Channel information for performing MU-MIMO may be obtained based on the pre-coding matrix of the SU-MIMO pre-coding codebook. A rank requested by the WTRU may be overridden if the unitary MU-MIMO codebook is a subset of the SU-MIMO pre-coding codebook. If not, a MU-MIMO pre-coding matrix with a largest correlation to the pre-coding matrix may be selected. A WTRU may send a pre-coding matrix for transmission to the WTRU along with a preferred interference matrix. A WTRU may send rank information and multiple right singular vectors for MU-MIMO.

Abstract: Methods for signaling precoding matrices used at the Node-B for data transmission with multiple user-multiple in multiple out (MU-MIMO) wireless communications. Precoding vectors may be efficiently signaled between wireless transmit/receive units and base stations using control channels, reference signals and blind detection of the precoding information.

Abstract: Data is estimated from a received vector comprising a plurality of communications. A received wireless signal is converted to a baseband signal, which is sampled to produce a received vector. Channel responses are estimated for the received communications. The noise variance is estimated. The noise variance is scaled by a scaling factor. Samples are processed using the estimated channel responses and the scaled noise variance to produce a spread data vector. The spread data vector is despread to recover the data of the received wireless signal.

Abstract: A code division multiple access communication system transmits a pilot and traffic signal over a shared spectrum. The pilot and traffic signal have an associated code and are received over the shared spectrum. The received signals are sampled and the samples are delayed to produce a window. A weighted value for each despread pilot code window sample is determined using an adaptive algorithm. Each window sample is despread with a traffic code. Each despread traffic code window sample is weighted according to a weight corresponding to its respective pilot code sample.

Abstract: A method for determining the validity of a most significant path in a wireless communication system wherein data is transmitted in frame units in a multipath environment begins by accumulating a correlated data sequence N times, each time at a frame offset apart from the previous time. A preliminary noise estimate (PNE) is calculated as an average of the accumulated data values. A preliminary noise threshold (PNT) is calculated according to the equation C1×PNE. A final noise estimate (FNE) is calculated as the average of accumulated data values below the PNT. A final noise threshold (FNT) is calculated according to the equation C2×FNE. The validity of the most significant path is determined if the most significant path value is greater than the FNT.

Abstract: The present invention is for a receiver incorporated into User Equipment (UE) or base stations of a code division multiple access (CDMA) communication system. The UE and base station are in communication with one of the plurality of base stations and receives a communication signal through the receiver. The communication signal is correlated using a delay locked code tracking loop, that estimates and tracks a channel delay. The tracking loop comprises a reference code generator and an interpolator for generating timed signal versions in response to said communication. A timed signal correlator, included in the tracking loop for correlating at least two of the timed signal versions with the code reference signal. The result of the correlation is used for generating an error signal. An automatic power normalization loop (APN), that is responsive to the interpolator, generates a power error signal that normalizes the error signal through a normalization circuit.

Abstract: A power control scheme for an enhanced Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA) physical uplink shared channel (PUSCH) is disclosed. In a first embodiment, when an uplink grant is configured for accumulation commands, the wireless transmit/receive unit (WTRU) combines the accumulation commands received in both the scheduling grant and the transmit power control physical downlink control channel. In a second embodiment, when an uplink grant is configured for absolute commands, the WTRU resets the accumulation control function immediately after receiving each absolute transmit power control command and then combines the absolute power control with the accumulation power control.

Abstract: Data is estimated from a received vector comprising a plurality of communications. A received wireless signal is converted to a baseband signal, which is sampled to produce a received vector. Channel responses are estimated for the received communications. The noise variance is estimated. The noise variance is scaled by a scaling factor. Samples are processed using the estimated channel responses and the scaled noise variance to produce a spread data vector. The spread data vector is despread to recover the data of the received wireless signal.

Abstract: A method for performing initial cell search in wireless communication system wherein unsuitable cells includes searching stored frequencies exhaustively and initial frequencies non-exhaustively. Initial frequencies may be searched exhaustively in certain circumstances. When performing exhaustive initial cell searches, primary synchronization codes that lead to unsuitable cells are excluded from subsequent initial cell searches performed on the same frequency.

Abstract: A method and apparatus for uplink synchronization during handover are disclosed. A wireless transmit/receive unit (WTRU) measures a downlink receipt timing difference between a source Node-B and a target Node-B. The WTRU calculates a target Node-B timing advance value based on the downlink receipt timing difference, a source Node-B timing advance value, and a relative downlink transmit timing difference between the target Node-B and the source Node-B. The WTRU then applies the target Node-B timing advance value in transmission to the target Node-B. The source Node-B may calculate the relative downlink transmit timing difference between the target Node-B and the source Node-B, and send it to the WTRU. The source Node-B may provide the source Node-B timing advance value more frequently during handover. The WTRU may measure the downlink receipt timing difference by averaging multiple first significant paths (FSPs) over a certain time window.

Abstract: A combined open loop and closed loop (channel quality indicator (CQI)-based) transmit power control (TPC) scheme with interference mitigation for a long term evolution (LTE) wireless transmit/receive unit (WTRU) is disclosed. The transmit power of the WTRU is derived based on a target signal-to-interference noise ratio (SINR) and a pathloss value. The pathloss value pertains to the downlink signal from a serving evolved Node-B (eNodeB) and includes shadowing. An interference and noise value of the serving eNodeB is included in the transmit power derivation, along with an offset constant value to adjust for downlink (DL) reference signal power and actual transmit power. A weighting factor is also used based on the availability of CQI feedback.

Abstract: In a time-division duplex (TDD) system, a reliable initialization scheme that is applicable to an automatic gain controller (AGC) at a base station is implemented in various forms depending on the availability of certain information such as signal-to-interference ratio (SIR), spreading factors and other parameters. A more accurate estimation of the initial control word of a gain-adjustable amplifier for one or more time slots is implemented. The scheme is applicable to AGC initialization for each time slot of the TDD system, but is also applicable to other systems of transmission, without limitation.

Abstract: A multiple-input multiple-output (MIMO) scheme uses precoding and feedback in a wireless communication system including a transmitter and a receiver. The system may use either a single codeword (SCW) or a double codeword (DCW). The precoding scheme is based on transmit beamforming (TxBF). Combined differential and non-differential feedback with periodic resetting is considered.

Abstract: A wireless communication system includes a wireless transmit/receive unit (WTRU). The WTRU is configured to generate at least one local codebook based on a baseline codebook, and select a codeword from the local codebook that is associated with feedback.

Abstract: A method and apparatus for scaling a soft bit for decoding in a wireless communication system are described. A scaling factor is calculated for a received symbol based on an estimated signal-to-noise ratio (SNR) of the received symbol and the scaling factor is applied to a soft bit of the received symbol. A multiple-input multiple-output (MIMO) scheme may be implemented to transmit multiple data streams. In such case, a soft bit of a received symbol on each data stream is scaled by a scaling factor for the received symbol on each data stream.