摘要:
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. The received prediction error is inverse quantized and subtracted from the predicted frequency response to yield a frequency response corresponding to that estimated at the transceiver.
摘要:
A Coordinated Multipoint (CoMP) cell controller performs network-centric link adaptation for User Equipment (UE) in the CoMP cell. The CoMP cell controller receives at least infrequent channel estimates from a UE in the CoMP cell, from which it estimates downlink channel and thermal noise at the UE. The CoMP cell controller is aware of the desired signal to be received at the UE, and the intra-CoMP cell interference to the UE caused by transmissions to other UEs in the CoMP cell. The CoMP cell receives from the UE reports of inter-CoMP cell interference caused by transmissions by other CoMP cells. Based on the downlink channel quality, the desired signal, the intra-CoMP cell interference, the inter-CoMP cell interference, and the thermal noise, the CoMP cell controller performs link adaptation by selecting modulation and coding schemes, and other transmission parameters, for an upcoming transmission duration (such as a TTI).
摘要:
Teachings presented herein offer reduced computational complexity for symbol sequence estimation, and also provide for the generation of soft bit values representing the reliability of that estimation. A demodulator is configured to generate these soft bit v allies by identifying a candidate value for each symbol in the sequence which is more likely than at least one other in a defined set of candidate values. Based on the candidate value identified for each symbol, the demodulator forms a reduced set of candidate values for the symbol by selecting as many additional candidate values from the defined set as are needed to have complementary bit values lot each bit value in that identified candidate value The demodulator calculates soft hit values for the symbol sequence based on a sequence estimation process w hose state space for each symbol is constrained to the cot responding reduced set.
摘要:
In a Coordinated Multi-point (CoMP) system, the base station (BS) in each serving cell ( or sector) is allowed to use not only its own antennas, but also the antennas of neighboring BSs to transmit to mobile terminals in the serving cell to form a floating CoMP cell The serving BS in each floating CoMP cell computes tentative linear preceding weights for transmissions from the coordinating BSs in the floating CoMP cell to users in the serving cell of the floating CoMP cell. The serving RS determines the power availability for transmit antennas in the floating CoMP cell that are shared with other floating CoMP cells, and scales the tentative preceding weights based on the power availability of the shared transmit antennas to determine final preceding weights so that the power constraints of the shared transmit antennas will not be violated.
摘要:
The present invention relates to a broadcast-centric cellular communication system that improves broadcast channel performance by exploiting the benefits of macro-diversity in a cellular communication system having a plurality of base stations that transmit signals within a plurality of associated cells. System-specific control information common to all cells is synchronously and simultaneously broadcast from multiple base stations using a broadcast channel that is identical across the entire system. Cell-specific control information is transmitted individually from each base station. Mobile stations use the broadcast information for initial synchronization to the system, and to obtain most relevant system information. After system synchronization, the mobile stations identify the connected cell through a physical layer characteristic, and perform initial access to the system. The invention furthermore relates to a mobile station for operating in such communication system and a method in said mobile station.
摘要:
A mobile phone is described herein that has control (or at least partial control) over which virtual antenna (s) in one or more base stations should be used 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 should be used 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.
摘要:
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.