Uplink Reference Signal for Time and Frequency Scheduling of Transmissions
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.
1 - 14 . (canceled)
15 . A method for dividing a total bandwidth in a single-carrier frequency division multiple access transmission system, having multiple user equipments and a serving Node B, in at least two contiguous and non-overlapping sub-bandwidths, said method comprising:
scheduling the signal transmission from a first portion of said user equipments in one of said at least two sub-bandwidths; and
scheduling the signal transmission from a second portion of said user equipments in a second of said at least two sub-bandwidths where said second portion of said user equipments and said second of at least two sub-bandwidths are entirely different than said first portion of said user equipments and said first of said at least two sub-bandwidths.
16 . The method of claim 15 , wherein said signal transmission from said multiple user equipments is in one of said at least two sub-bandwidths during a first time period and is in a second of said at least two sub-bandwidths during a second time period.
17 . The method of claim 16 , wherein either of said first time period and said second time period is longer than a transmission time interval.
18 . The method of claim 15 , wherein the size of said first and the size of said second of at least two sub-bandwidths changes after a time period.
19 . The method of claim 16 , wherein said time period is longer than a transmission time interval.
20 . The method of claim 15 , wherein a user equipment having M transmit antennas is regarded as M separate user equipments having one transmit antenna.
21 . A method for transmitting a reference signal in a frequency division multiple access transmission system having a total bandwidth and having multiple user equipments and a serving Node B, said method comprising:
dividing said total bandwidth into at least two contiguous and non-overlapping sub-bandwidths; and
transmitting a reference signal substantially occupying one of said at least two contiguous and non-overlapping sub-bandwidths.
22 . The method of claim 21 , wherein said reference signal is used to provide a channel quality estimate to perform channel dependent scheduling.
23 . The method of claim 21 , wherein said reference signal is used to provide a channel estimate for a user equipment also having a data transmission.
24 . The method of claim 21 , wherein said reference signal is transmitted using code division multiplexing.
25 . The method of claim 21 , wherein said reference signal is transmitted using frequency division multiplexing.
26 . The method of claim 21 , wherein said reference signal is transmitted using a hybrid of code division multiplexing and frequency division multiplexing.
27 . The method of claim 21 , wherein said reference signal for a user equipment substantially occupies a first of said at least two sub-bandwidths in a first transmission period and substantially occupies a second of said at least two sub-bandwidths in a second transmission period.
28 . The method of claim 21 , wherein said scheduling sub-bandwidth is signaled to a UE by the serving Node B.
29 . The method of claim 28 , wherein said signaling occurs less frequently than the transmission time interval duration.
30 - 51 . (canceled)