摘要:
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. A transmitter may be configured to facilitate impairment correlation determinations by wireless communication receivers operating in MIMO/MISO environments, by signaling one or more values, e.g., data-to-pilot signal transmit power ratios and/or transmit antenna power distributions for the data and pilot signals.
摘要:
A method and apparatus for generating channel quality information, such as may be used for transmit link adaptation, provide different operating modes, such as a first mode that may be used when propagation channel estimates are not reliable, and a second mode that may be used when the propagation channel estimates are reliable. In one or more embodiments, channel quality information is generated using receiver performance information that characterizes receiver performance in terms of a defined channel quality metric, e.g., supported data rates, for different values of receiver input signal quality over a range of propagation channel realizations. Channel quality information can be generated by selecting channel quality metrics according to receiver input signal quality and a desired probability of meeting a defined performance requirement over a range of propagation channel realizations, or by selecting channel quality metrics according to receiver input signal quality and particularized propagation channel realizations.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A channel response may be estimated from training symbols that are received over a channel, by determining an initial channel estimate from the training symbols and applying bias to the initial channel estimate to obtain a biased channel estimate. The biased channel estimate may then be used to demodulate a signal that is received over the channel.
摘要:
Processing of loop-back information returned by one or more mobile stations that are served by a wireless communication network permits the network to compensate its transmit signals for increased transmission efficiency and reduced signal interference at the mobile stations. Generally, the network forms one or more transmit signals as a combination of different signals intended for the different mobile stations, and remembers transmit information associated with these transmit signals. The mobile stations return loop-back signals to the network, which determines transmit signal compensation information by comparing loop-back information to memorized information. The mobile stations may loop-back samples from composite received signals, from processed received signal samples, or loop-back estimates. In the first case, processing at the network involves compensating the combined transmit signals at the transmit modulation rate, while the second case involves symbol rate processing of the individual information streams intended for the different mobile stations.
摘要:
A receiver reduces interference in a received symbol of interest attributable to an interfering symbol using knowledge of the symbol spreading codes. The receiver comprises a plurality of correlators generating despread values for the received symbol of interest and the interfering symbol, and a combiner to combine the despread values using combining weights calculated based on spreading code correlations between spreading codes for the received symbol of interest and the interfering symbol.
摘要:
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. A transmitter may be configured to facilitate impairment correlation determinations by wireless communication receivers operating in MIMO/MISO environments, by signaling one or more values, e.g., data-to-pilot signal transmit power ratios and/or transmit antenna power distributions for the data and pilot signals.
摘要:
A frequency domain representation of a whitening filter is made to depend on essentially one unknown, namely, a scaling factor that is based on an estimated ratio of total base station power to the power spectral density (PSD) of inter-cell interference plus noise. In turn, that scaling factor can be computed based on the modeling terms used in a parametric model of the impairment correlations for a received communication signal. Preferably, the model comprises an interference impairment term scaled by a first model fitting parameter, and a noise impairment term scaled by a second model fitting parameter. Further, the scaling factor can be computed by directly estimating total base station transmit power and the PSD of inter-cell interference plus noise. In any case, the whitening filter can be used in whitening a received communication signal in conjunction with channel equalization processing or RAKE receiver processing, for example.