Abstract:
Methods for improving uplink communications in a Wideband Code Division Multiple Access (WCDMA) communication system, wherein mobile terminals can transmit at various transmission power levels. In a mobile terminal, the method includes the steps of receiving a configuration message having at least one of a power offset parameter and a maximum number of retransmission attempts parameter; when the mobile terminal performs a non-scheduled transmission, it transmits according to the parameters contained in the configuration message. In a network node, the method includes the steps of transmitting to at least one mobile terminal the configuration message having at least one of a power offset parameter and a maximum number of retransmission attempts parameter; and, adjusting a power setting for the transmission of acknowledgement or negative-acknowledgement messages from the wireless network to one or more of mobile terminals.
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. 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.
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. 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.
Abstract:
In a receive node of a wireless network, an iterative multi-user multi-stage interference cancellation receiver is used. After each stage of interference cancellation, interference characteristics change. An adaptive strategy is used in which after each stage of interference cancellation, impairment covariance is parametrically updated and combining weights of the receiver are adapted to reflect the updated impairment covariance.
Abstract:
A joint detector that improves the performance of receiving a downlink control channel signal for a near-end mobile terminal in the presence of a stronger control channel signal addressed to a far-end mobile terminal sharing the same OVSF, or channelization, code through the use of orthogonal signature sequences. Depending on the specific embodiment, the joint detector may produce the desired bits for the control signal of interest, or may produce detected bits for all control signals sharing the same OVSF code. The joint detector despreads and combines the received code-multiplexed signal, utilizing knowledge of the cross correlations of the set of signature sequences and time-varying channel coefficients to alleviate performance degradation caused by interference from other signals. In various embodiments, the joint detector may be implemented as a modified decorrelating detector, a modified MMSE detector, a modified LS estimator detector, a successive interference-canceling detector, or a jointly hypothesized detector.
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. 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.
Abstract:
A receive signal processor jointly detects two or more symbols in a signal-of-interest in the presence of one or more other MIMO signals. The signal-to-interference-plus-noise ratio for each signal-of-interest is determined by computing per-subcarrier signal-to-interference-plus-noise ratios for a plurality of subcarriers allocated to the signals-of-interest, and computing a total signal-to-interference-plus-noise ratio for the subcarriers based on the per-subcarrier signal-to-interference-plus-noise ratios of the subcarriers. A controller determines one or more transmission formats for uplink transmissions based on the signal-to-interference-plus-noise ratios. The process of computing per-subcarrier signal-to-interference-plus-noise ratio reflects the amount of MIMO interference already cancelled or still remaining in the signal arriving at the joint detector.
Abstract:
Techniques for generating soft values for parity bits in a convolutional decoding process are disclosed. An exemplary method comprises, for each of at least one iteration in at least one soft-input soft-output decoder, calculating intermediate probability values for each possible transition between a first plurality of candidate decoder states at a first time and a second plurality of candidate decoder states at a second time. Two or more partial sums are then computed from the intermediate probability values, wherein the partial sums correspond to possible combinations of two or more systematic bits, two or more parity bits, or at least one systematic bit and at least one parity bit. Soft values, such as log-likelihood values, are then estimated for each of at least one systematic bit and at least one parity bit of the received communications data corresponding to the interval between the first and second times, based on the partial sums.
Abstract:
Techniques for generating soft values for parity bits in a convolutional decoding process are disclosed. An exemplary method comprises, for each of at least one iteration in at least one soft-input soft-output decoder, calculating intermediate probability values for each possible transition between a first plurality of candidate decoder states at a first time and a second plurality of candidate decoder states at a second time. Two or more partial sums are then computed from the intermediate probability values, wherein the partial sums correspond to possible combinations of two or more systematic bits, two or more parity bits, or at least one systematic bit and at least one parity bit. Soft values, such as log-likelihood values, are then estimated for each of at least one systematic bit and at least one parity bit of the received communications data corresponding to the interval between the first and second times, based on the partial sums.
Abstract:
In a selective MIMO system, the mobile station provides channel quality feedback for one or more possible transmission mode. The mobile station provides channel quality feedback for a first mode regardless of channel conditions and determines whether to provide feedback for one or more additional modes based on current channel conditions.