摘要:
Embodiments of the invention provide method for allocating CAZAC pilot (reference signal) sequences in multiple access OFDMA systems, or alternatively, in multiple access DFT-spread OFDM(A) systems (or SC-FDMA). Reference signal transmissions from different mobiles can either be distinguished by use of disjoint sub-carriers (frequency division orthogonality), or alternatively by use of distinct cyclic shifts of one base CAZAC sequence. In a wireless cellular network, neighboring cells should utilize different CAZAC sequences, in order to mitigate out-of-cell interference.
摘要:
Embodiments of the invention provide method and structure for boosting pilot signal power relative to data signal power. The velocity of user equipment is obtained. The velocity measurement is used in determining the transmission power of the pilot signal and applying the increase to a plurality of pilots and decreasing the data signal power by a proportional amount.
摘要:
A method for multiplexing reference signal (RS) transmissions from user equipments (UEs), with the RS having a bandwidth larger than the data signal bandwidth (distributed RS) is provided. A transmission time interval (TTI) comprises of one or more sub-frames and each sub-frame comprises of at least two RS transmission periods and a plurality of data signal transmission periods. A distributed RS is transmitted during at least one of the at least two RS transmission periods in at least one of the sub-frames comprising the TTI. During the remaining RS transmission periods, for a UE having a data signal transmission, the RS bandwidth is substantially the same as the data signal bandwidth (localized RS). The total system bandwidth is divided into contiguous, non-overlapping sub-bandwidths, called reference signal multiplexing blocks (RSMBs). Transmission of distributed RS occurs within an RSMB and does not cross over different RSMBs. The size and number of RSMBs can be re-configurable in time and a re-configuration period is much larger than the TTI duration.
摘要:
A method for multiplexing reference signal (RS) transmissions from user equipments (UEs), with the RS having a bandwidth larger than the data signal bandwidth (distributed RS) is provided. A transmission time interval (TTI) comprises of one or more sub-frames and each sub-frame comprises of at least two RS transmission periods and a plurality of data signal transmission periods. A distributed RS is transmitted during at least one of the at least two RS transmission periods in at least one of the sub-frames comprising the TTI. During the remaining RS transmission periods, for a UE having a data signal transmission, the RS bandwidth is substantially the same as the data signal bandwidth (localized RS). The total system bandwidth is divided into contiguous, non-overlapping sub-bandwidths, called reference signal multiplexing blocks (RSMBs). Transmission of distributed RS occurs within an RSMB and does not cross over different RSMBs. The size and number of RSMBs can be re-configurable in time and a re-configuration period is much larger than the TTI duration.
摘要:
An embodiment of the present invention uses estimates of delay spreads of transmissions from user equipments (UEs) to a NodeB to determine a set of transmission parameters for the UEs reference signals. In an exemplary embodiment, the transmission parameters for reference signals include cyclic shifts. Thus, embodiments include a set of allocated cyclic shift values that are tailored to the delay spreads. The set of allocated cyclic shift values are used by a corresponding set of UE being served by a NodeB to form references signals. Each UE uses the allocated cyclic shift to form its reference signal by applying the cyclic shift to a modified reference sequence. The modified reference sequence can be generated from a Constant-Amplitude-Zero-Auto Correlation (CAZAC) sequence. The set of allocated cyclic shift values can be updated periodically to account for changes of delay spreads, which can be caused by physical movements of the set of UEs.
摘要:
Embodiments of the invention apply block spreading to transmitted signals to increase the number orthogonally multiplexed signals. The principle of the disclosed invention can be applied to reference signals, acknowledgement signals, and channel quality indication signals. In any given time interval, the set of transmitted signals is defined by two sequences: the baseline sequence, and the block spreading sequence. Different transmitters using the same baseline sequence can be identified by using different block spreading sequences.
摘要:
A method for multiplexing reference signal (RS) transmissions from user equipments (UEs), with the RS having a bandwidth larger than the data signal bandwidth (distributed RS) is provided. A transmission time interval (TTI) comprises of one or more sub-frames and each sub-frame comprises of at least two RS transmission periods and a plurality of data signal transmission periods. A distributed RS is transmitted during at least one of the at least two RS transmission periods in at least one of the sub-frames comprising the TTI. During the remaining RS transmission periods, for a UE having a data signal transmission, the RS bandwidth is substantially the same as the data signal bandwidth (localized RS). The total system bandwidth is divided into contiguous, non-overlapping sub-bandwidths, called reference signal multiplexing blocks (RSMBs). Transmission of distributed RS occurs within an RSMB and does not cross over different RSMBs. The size and number of RSMBs can be re-configurable in time and a re-configuration period is much larger than the TTI duration.
摘要:
Methods and apparatus to schedule uplink transmissions in wireless communication systems, such as cellular communication systems, are disclosed. A disclosed example method comprises measuring channel conditions for a plurality of equipment devices at a base transceiver station of a wireless communication system, dividing an operating bandwidth of the base transceiver station into two or more non-overlapping portions, and instructing a first of the plurality of user equipment devices to transmit a sounding reference signal in a first non-overlapping portion during a sounding reference signal transmission interval.
摘要:
A method and apparatus for defining transmission parameters of user equipment reference signals. The method includes estimating channel delay spreads of a plurality of user equipments scheduled for transmission at a particular transmission time period or sub-frame in an uplink for communication with a NodeB, and allocating transmission parameters to each scheduled user equipment of the plurality of user equipments in accordance to the delay spreads of the plurality of user equipments scheduled for transmission in the particular time period or sub-frame, wherein the parameters comprises a cyclic shift allocated to each m-th user equipment equal to the sum of a delay spread and a timing uncertainty of each of the previous m-1 user equipments.
摘要:
A method for multiplexing reference signal (RS) transmissions from user equipments (UEs), with the RS having a bandwidth larger than the data signal bandwidth (distributed RS) is provided. A transmission time interval (TTI) comprises of one or more sub-frames and each sub-frame comprises of at least two RS transmission periods and a plurality of data signal transmission periods. A distributed RS is transmitted during at least one of the at least two RS transmission periods in at least one of the sub-frames comprising the TTI. During the remaining RS transmission periods, for a UE having a data signal transmission, the RS bandwidth is substantially the same as the data signal bandwidth (localized RS). The total system bandwidth is divided into contiguous, non-overlapping sub-bandwidths, called reference signal multiplexing blocks (RSMBs). Transmission of distributed RS occurs within an RSMB and does not cross over different RSMBs. The size and number of RSMBs can be re-configurable in time and a re-configuration period is much larger than the TTI duration.