摘要:
Techniques for transmitting data using a combination of explicit cyclic delay and implicit cyclic delay are described. A transmitter may perform first processing for cyclic delay diversity (or explicit cyclic delay processing) based on a first set of cyclic delay values known to a receiver. The transmitter may perform precoding based on a precoding matrix either before or after the explicit cyclic delay processing. The transmitter may perform second processing for cyclic delay diversity (or implicit cyclic delay processing) based on a second set of cyclic delay values unknown to the receiver. The transmitter may perform both explicit and implicit cyclic delay processing for data and may perform only implicit cyclic delay processing for pilot. One entity may select the first set of cyclic delay values and inform the other entity. The transmitter may autonomously select the second set of cyclic delay values without informing the receiver.
摘要:
Techniques for sending a MIMO transmission using a combination of cyclic delay diversity and precoding are described. A set of delays (e.g., zero delay, small delay, and large delay) for cyclic delay diversity and a set of precoding matrices may be supported. In one design, a Node B may select a delay specifically for a UE or for a set of UEs served by the Node B. In another design, a UE may evaluate different combinations of precoding matrix and delay, determine the combination with the best performance, and send this combination of precoding matrix and delay to the Node B. The Node B may perform precoding with the precoding matrix and then processing for cyclic delay diversity based on the selected delay. Alternatively, the Node B may perform processing for cyclic delay diversity based on the selected delay and then precoding with the precoding matrix.
摘要:
Techniques for sending a MIMO transmission using a combination of cyclic delay diversity and precoding are described. A set of delays (e.g., zero delay, small delay, and large delay) for cyclic delay diversity and a set of precoding matrices may be supported. In one design, a Node B may select a delay specifically for a UE or for a set of UEs served by the Node B. In another design, a UE may evaluate different combinations of precoding matrix and delay, determine the combination with the best performance, and send this combination of precoding matrix and delay to the Node B. The Node B may perform precoding with the precoding matrix and then processing for cyclic delay diversity based on the selected delay. Alternatively, the Node B may perform processing for cyclic delay diversity based on the selected delay and then precoding with the precoding matrix.
摘要:
Techniques for transmitting data using a combination of explicit cyclic delay and implicit cyclic delay are described. A transmitter may perform first processing for cyclic delay diversity (or explicit cyclic delay processing) based on a first set of cyclic delay values known to a receiver. The transmitter may perform precoding based on a precoding matrix either before or after the explicit cyclic delay processing. The transmitter may perform second processing for cyclic delay diversity (or implicit cyclic delay processing) based on a second set of cyclic delay values unknown to the receiver. The transmitter may perform both explicit and implicit cyclic delay processing for data and may perform only implicit cyclic delay processing for pilot. One entity may select the first set of cyclic delay values and inform the other entity. The transmitter may autonomously select the second set of cyclic delay values without informing the receiver.
摘要:
Techniques for supporting MIMO transmission with layer permutation are described. In one aspect, multiple codewords may be generated for transmission from multiple antennas (e.g., virtual antennas), with the number of codewords being less than the number of antennas. Each codeword may be mapped across the multiple antennas. Two codewords may be generated. For rank 3, the first codeword may be mapped to one layer (or one antenna on each subcarrier), and the second codeword may be mapped to two layers (or two antennas on each subcarrier). For rank 4, each codeword may be mapped to two layers. In another aspect, a base CQI indicative of an average signal quality may be determined. A delta CQI indicative of improvement over the average signal quality may also be determined. In yet another aspect, selection may be performed with different penalty factors for different ranks or number of codewords.
摘要:
Techniques for supporting MIMO transmission with layer permutation are described. In one aspect, multiple codewords may be generated for transmission from multiple antennas (e.g., virtual antennas), with the number of codewords being less than the number of antennas. Each codeword may be mapped across the multiple antennas. Two codewords may be generated. For rank 3, the first codeword may be mapped to one layer (or one antenna on each subcarrier), and the second codeword may be mapped to two layers (or two antennas on each subcarrier). For rank 4, each codeword may be mapped to two layers. In another aspect, a base CQI indicative of an average signal quality may be determined. A delta CQI indicative of improvement over the average signal quality may also be determined. In yet another aspect, selection may be performed with different penalty factors for different ranks or number of codewords.
摘要:
A method for controlling power in a wireless network is provided. The method includes determining a relative power parameter at a wireless device such as a mobile wireless terminal and receiving a load parameter at the wireless device, where the load parameter is associated with at least one other wireless cell. The method includes adjusting transmit power of the wireless device in view of the relative power parameter and the load parameter. In another embodiment, the transmit power can be controlled in view of an absolute power spectral density parameter.
摘要:
Systems and methodologies are described that facilitate applying cyclic delay diversity (CDD) and precoding to wireless transmissions. In particular, data vectors to be transmitted to a number of receive antennas of a receiver can be transformed to a virtual antenna domain. CDD can be applied to this domain followed by precoding to allow the benefits of precoding to remain though CDD is applied. In this regard, the resulting signals can be transmitted without pouring transmission energy into null spaces unreachable by receiving devices.
摘要:
Systems and methodologies are described that facilitate applying cyclic delay diversity (CDD) and precoding to wireless transmissions. In particular, data vectors to be transmitted to a number of receive antennas of a receiver can be transformed to a virtual antenna domain. CDD can be applied to this domain followed by precoding to allow the benefits of precoding to remain though CDD is applied. In this regard, the resulting signals can be transmitted without pouring transmission energy into null spaces unreachable by receiving devices.
摘要:
Techniques for transmitting synchronization signals to assist user equipments (UEs) perform cell searches are described. In one design, a base station for a cell may generate and transmit a primary synchronization signal and a secondary synchronization signal, which may be used by the UEs for initial cell search at power up. The base station may also generate and transmit one or more beacon signals, which may be used by the UEs for neighbor cell search to detect for neighbor cells. The number of beacon signals to transmit and the set of subcarriers usable for each beacon signal may be determined based on the system bandwidth. Each beacon signal may be mapped to one subcarrier in the set of subcarriers in each beacon symbol period. This one subcarrier may be determined based on a beacon hopping pattern or a beacon code and may be dependent on a cell identifier (ID).