SYSTEM AND METHOD FOR SIGNAL DENSITY REDUCTION IN FREQUENCY DOMAIN
FIG4 illustrates an example table of frequency domain density reduction information according to example embodiments described herein
According to an example embodiment, a frequency domain density reduction rate indicator is provided to reduce the overhead associated with indicating the frequency domain density reduction rate. The frequency domain density reduction rate indicator may be in the form of an index into a table (or some other similar data arrangement). FIG4 illustrates an example table 400 of frequency domain density reduction rate information. Table 400 includes a frequency domain density reduction rate indication 405 and associated CSI-RS transmission frequency 410. As an illustrative example, an indicator of 1 indicates that every other PRB conveys the CSI-RS, while an indicator of 0 indicates that every PRB conveys the CSI-RS.
table
1
Step
100
communications system
400
table
2
Step
105
access node
405
density reduction rate indication
110
including UEs
410
associated CSI-RS transmission frequency
['1. A method for operating an access node, the method comprising: sending (509), by the access node to a user equipment, UE, a frequency domain density reduction rate indicator and a frequency shift index indicator for one or more channel state indicator reference signal, CSI-RS, resources, wherein the frequency domain density reduction rate indicator indicates a number of physical resource blocks, PRBs, skipped between successive CSI-RS transmissions and the frequency shift index indicator indicates a shift of a CSI-RS starting PRB; wherein the frequency domain density reduction rate indicator and/or the frequency shift index indicator corresponding to each CSI-RS resource in an active set of K CSI-RS resources are sent during a radio resource control, RRC, configuration stage of a CSI-RS resource configuration process; wherein at least one frequency domain density reduction rate indicator and/ or at least one frequency shift index indicator configured during the RRC configuration stage is reconfigured for at least one CSI-RS resource in an activated set of N CSI-RS resources during an activation/release stage of the CSI-RS resource configuration process by sending, to the UE, uplink grants and/or medium access control, MAC, control elements, CE; and wherein at least one frequency domain density reduction rate indicator and/or at least one frequency shift index indicator configured during the RRC configuration stage and/ or at least one CSI-RS resource in the activated set of N CSI-RS resources configured during the activation/ release stage of the CSI-RS resource configuration process is reconfigured by sending, to the UE, downlink control information, DCI.']