Abstract: A radio base station, user equipment (UE), and method of control signaling in wireless communication systems. Control information is transferred from a base station to at least one UE, via a plurality of common pilot channels. A set of unique pilot sequences is predefined, and the base station assigns specific pilot sequences from the set of pilot sequences to specific common pilot channels, forming a pilot sequence assignment pattern representing specific control information. The UE, having knowledge of the relations between pilot sequence assignment patterns and control information, interprets the received pilot sequence assignment pattern as specific control information. The method is particularly well suited for broadcast type control information.

Abstract: A communication device is described herein that has control (or at least partial control) over which virtual antenna(s) in one or more base stations to use for transmissions. In one embodiment, the mobile phone performs the following steps: (1) receives an antenna subset list (from the scheduling unit) which identifies a configuration of virtual antennas that is associated with the base station(s); (2) uses the antenna subset list to select which virtual antenna(s) in the configuration of virtual antennas to use for transmissions; and (3) sends an antenna selection signal (to the scheduling unit) which contains information that instructs/requests the base station(s)/scheduling unit to use the selected virtual antenna(s) for transmissions.

Abstract: A UE in a wireless communication network transmits succinct, direct channel state information to the network, enabling coordinated multipoint calculations such as joint processing, without substantially increasing uplink overhead. The UE receives and processes reference symbols over a set of non-uniformly spaced sub-carriers, selected according to a scheme synchronized to the network. The frequency response for each selected sub-carrier is estimated conventionally, and the results quantized and transmitted to the network on an uplink control channel. The non-uniform sub-carrier selection may be synchronized to the network in a variety of ways.

Abstract: The present invention relates to control signaling in wireless communication systems. In particular, the present invention relates to control signaling in MIMO based communication systems. In the method according to the invention control information is transferred from a base station to at least one user equipment, via a plurality of common pilot channels. A set of unique pilot sequences has been pre-defined, and the base station assigns specific pilot sequences from the set of pilot sequences to specific common pilot channels, forming a pilot sequence assignment pattern representing a specific control information. The user equipment, having knowledge of the relations between pilot sequence assignment patterns and control information, interprets the received pilot sequence assignment pattern as specific control information. The method is particularly well suited for broadcast type control information.

Abstract: Accurate downlink channel estimates are calculated based on infrequently transmitted Channel State Information (CSI) feedback data from a UE 20. A plurality of non-uniformly spaced digital CSI feedback samples, representing the frequency response of a downlink communication channel, is received from the UE. The received CSI feedback samples are demodulated and inverse quantized. A time domain tap delay channel model is generated from the inverse quantized CSI feedback samples. The time domain tap delay channel model may be frequency-transformed to obtain a reconstructed frequency response of the downlink communication channel in the frequency domain. Alternatively, channel delays may be estimated based on prior delays and/or known references signals transmitted on the uplink. Channel estimates between CSI reporting instances may be predicted, such as by a sample & hold or a linear predictor. The delays may be presumed fixed, and Kalman filter coefficients evolved over time.

Abstract: A communication device is described herein that has control (or at least partial control) over which virtual antenna(s) in one or more base stations to use for transmissions. In one embodiment, the mobile phone performs the following steps: (1) receives an antenna subset list (from the scheduling unit) which identifies a configuration of virtual antennas that is associated with the base station(s); (2) uses the antenna subset list to select which virtual antenna(s) in the configuration of virtual antennas to use for transmissions; and (3) sends an antenna selection signal (to the scheduling unit) which contains information that instructs/requests the base station(s)/scheduling unit to use the selected virtual antenna(s) for transmissions.

Abstract: The required bitrate for reporting channel state information from a network transceiver to the network is dramatically reduced, while maintaining fidelity of channel estimates, by exploiting prior channel estimates and the time correlation of channel response. For a selected set of sub-carriers, the transceiver estimates channel frequency response from pilot signals. The transceiver also predicts the frequency response for each selected sub-carrier, by multiplying a state vector comprising prior frequency response estimate and a coefficient vector comprising linear predictive coefficients. The predicted frequency response is subtracted from the estimated frequency response, and the prediction error is quantized and transmitted to the network. The network maintains a corresponding state vector and predictive coefficient vector, and also predicts a frequency response for each selected sub-carrier.

Abstract: A User Equipment in a wireless communication network includes a multiplicity of antennas, from which a subset of antennas is selected using a selection scheme synchronized to the network. A set of sub-carriers is selected from a plurality of sub-carriers using a selection scheme synchronized to the network. The UE receives a plurality of known reference symbols over the selected set of sub-carriers and through the selected subset of antennas. A frequency response for each selected sub-carrier is estimated over only the selected subset of antennas. The results are quantized and transmitted to the network on an uplink control channel.

Abstract: Multi-antenna transmission control presented herein involves generating a set of virtual channel realizations at the transmitter that shares the same second-order statistics as the actual channel realizations observed for a targeted receiver. By making the control-related quantities of interest at the transmitter depend on the long-term statistics of the channel, the actual channel realizations are not needed for transmission control, e.g., for accurate Multiple-Input-Multiple-Output (MIMO) preceding. As such, the use of virtual channel realizations enables transmission control that approaches the “closed-loop” channel capacity that would be provided by full feedback of the (instantaneous) actual channel realizations, without requiring the overhead signaling burden that attends full feedback.

Abstract: A wireless communication receiver improves signal impairment correlation estimation in MIMO/MISO systems by considering different transmit power allocations and different transmit antenna power distributions in its impairment correlation calculations. The receiver may be implemented in according to a variety of architectures, including, but not limited to, Successive Interference Cancellation (SIC) Generalized RAKE (G-RAKE), Joint Detection (JD) G-RAKE, and Minimum Mean Squared Error (MMSE) G-RAKE. Regardless of the particular receiver architecture adopted, the improved impairment correlations may be used to calculate improved (RAKE) signal combining weights and/or improve channel quality estimates for reporting by receivers operating in Wideband CDMA (W-CDMA) systems transmitting HSDPA channels via MIMO or MISO transmitters.

Abstract: A method for determining antenna weights for use in transmitting data from a plurality of base stations to a user device is disclosed. The antenna weights are determined using an input covariance matrix (S), and the input covariance matrix is determined subject to a predetermined power constraint and a predetermined, non-zero interference constraint.

Abstract: The present invention relates to a method and arrangement to enhance the communication performance in wireless communication systems. The method of the invention provides better adjustment of reported SINR in MIMO, and PARC-MIMO based communication systems. According to the method information relating to signal-to-interference-plus-noise ratio is determined by the user equipment and reported to the base station. The base station adjust reported SINRs using a model of the SINR dependences of power and code allocation. The dependences is modeled by a function comprising a first parameter relating only to power allocation and a second parameter relating only to code allocation. The first parameter has a power allocation exponent and the second parameter has a code allocation exponent. Both the power allocation exponent and the code allocation exponent are data stream dependent.

Abstract: In a wireless network, plural downlink signals from plural base stations are transmitted to a terminal. The plural downlink signals all carry the same information to the terminal. The terminal provides feedback on the downlink channels. The feedback provides information on the taps of the channels. The amount of information fed back is constrained. Based on the feedback, transmission parameters of the downlink signals are adjusted. The process of transmitting, providing feedback, and adjusting the parameters continue so that the energy of the downlink signal is enhanced at the terminal location and suppressed elsewhere. Beam forming can be used to further suppress the energy signature at locations other than the terminal location.

Abstract: In a wireless network, plural downlink signals from plural base stations are transmitted to a terminal. The plural downlink signals all carry the same information to the terminal. The terminal provides feedback on the downlink channels. The feedback provides information on the taps of the channels. The amount of information fed back is constrained. Based on the feedback, transmission parameters of the downlink signals are adjusted. The process of transmitting, providing feedback, and adjusting the parameters continue so that the energy of the downlink signal is enhanced at the terminal location and suppressed elsewhere. Beam forming can be used to further suppress the energy signature at locations other than the terminal location.

Abstract: An adaptive transmission scheme provides multiple levels of adaptation. At a first level, a selection is made between a limited feedback or limited feedback scheme and a rich feedback scheme. At a second level of adaptation, a diversity mode is selected. Additional levels of adaptation could be employed.

Abstract: A method for processing signals to be transmitted in a MIMO system from a transmitter having at least two transmitting antennas to a receiver having at least two receiving antennas on a frequency selective communication channel. The method comprises estimating elements of a channel matrix H(q?1) based on time delays and complex valued coefficients associated with the communication channel to provide an estimated frequency variation function of each element of the channel matrix, and pre-coding the signals to be transmitted based on the estimated frequency variation function for each element. The invention also relates to a MIMO system; and a transmitter and a receiver for use in a MIMO system.

Abstract: A receiver and a method are described herein for reducing an amount of channel state information related to a transmit channel correlation matrix ?TX that is feedback to a transmitter. In addition, to a transmitter and a method are described herein for reconstructing the transmit channel correlation matrix ?TX using the reduced channel state feedback information received from the receiver.

Abstract: An apparatus for estimating a channel response associated with a multiple input/multiple output (MIMO) system includes an antenna that receives multiple pilot symbols, each of the multiple pilot symbols transmitted from a different one of multiple transmit antennas of a transmitter in the MIMO system. The apparatus further includes a channel estimator that determines spatial, time and frequency correlations of channels of the MIMO system among the multiple transmit antennas when estimating a channel response associated with the MIMO system based on multiple ones of the received plurality of pilot symbols.

Abstract: The required bitrate for reporting channel state information from a network transceiver to the network is dramatically reduced, while maintaining fidelity of channel estimates, by exploiting prior channel estimates and the time correlation of channel response. For a selected set of sub-carriers, the transceiver estimates channel frequency response from pilot signals. The transceiver also predicts the frequency response for each selected sub-carrier, by multiplying a state vector comprising prior frequency response estimate and a coefficient vector comprising linear predictive coefficients. The predicted frequency response is subtracted from the estimated frequency response, and the prediction error is quantized and transmitted to the network. The network maintains a corresponding state vector and predictive coefficient vector, and also predicts a frequency response for each selected sub-carrier.

Abstract: A receiver and receive processing method described herein improves the accuracy of channel estimates by correcting for the assumption that the Doppler shift (or rate-of-change-of-delay) stays constant for each frequency within a signal bandwidth of a received signal. To that end, a receiver according to the present invention comprises a channel processor having multiple processing units. A first processing unit processes reference values (e.g., pilot signals) received for each of a plurality of frequencies within a signal bandwidth at a plurality of different signal times (or the complex propagation channel coefficients estimated therefrom) to determine a set of complex wave amplitudes either for each of multiple frequencies in the signal bandwidth or for each of the different signal times.