Configuration of rank indicator reporting instances
A method for setting a periodicity and an offset in rank indicator (RI) reporting in a user equipment in a wireless communication system receives a radio resource control (RRC) signal from a base station, decodes a RI periodicity and offset configuration index, sets the periodicity and offset in accordance with said decoded periodicity and offset configuration index and reports a RI according to the set periodicity and offset. The periodicity is an integer and reporting a RI reports with equal the product of the periodicity and a period of reporting of the channel quality indicator (CQI) and the precoding matrix indicator (PMI).
1. A user equipment in a wireless communication system operable to:
receive a radio resource control (RRC) signal from a base station;
decode a rank indicator (RI) periodicity and offset configuration index I RI transmitted in the received RRC signal;
set a periodicity M RI and an offset N OFFSET,RI in accordance with said decoded I RI , where M RI is an integer; and
report a RI to the base station via a radio frequency signal according to said set periodicity M RI and offset N OFFSET,RI having a period equal to the product of the periodicity M RI multiplied by a period of reporting of a channel quality indicator (CQI) and a precoding matrix indicator (PMI).
2. The use equipment of claim 1 , wherein:
said user equipment is further operable to set the periodicity M RI and the offset N OFFSET,RI
if 0≦I RI ≦159 set the periodicity M RI equal to 1 and the offset N OFFSET,RI equal to −I RI ,
if 160≦I RI ≦319 set the periodicity M RI equal to 2 and the offset N OFFSET,RI equal to −I RI +160,
if 320≦I RI ≦479 set the periodicity M RI equal to 5 and the offset N OFFSET,RI equal to −I RI +320,
if 480≦I RI ≦639 set the periodicity M RI equal to 10 and the offset N OFFSET,RI equal to −I RI +480,
if 640≦I RI ≦799 set the periodicity M RI equal to 20 and the offset N OFFSET,RI equal to −I RI +640, and
if 800≦I RI ≦959 set the periodicity M RI equal to 40 and the offset N OFFSET,RI equal to −I RI +800.
3. The user equipment of claim 2 , wherein:
said user equipment is further operable to not report a RI if I RI =960.
4. A user equipment in a wireless communication system operable to:
receive a radio resource control (RRC) signal from a base station;
decode a RI periodicity and offset configuration index I RI transmitted in a received RRC signal;
set the periodicity M RI and the offset N OFFSET,RI by setting the offset N OFFSET,RI equal to −I RI +n, wherein n is a positive integer constant; and
report a RI to the base station via a radio frequency signal according to said set periodicity M RI and offset N OFFSET,RI .
5. The use equipment of claim 4 , wherein:
said user equipment is further operable to set the periodicity M RI and the offset N OFFSET,RI
if 0≦I RI ≦159 set the periodicity M RI equal to 1 and the offset N OFFSET,RI equal to −I RI ,
if 160≦I RI ≦319 set the periodicity M RI equal to 2 and the offset N OFFSET,RI equal to −I RI +160,
if 320≦I RI ≦479 set the periodicity M RI equal to 5 and the offset N OFFSET,RI equal to −I RI +320,
if 480≦I RI ≦639 set the periodicity M RI equal to 10 and the offset N OFFSET,RI equal to −I RI +480,
if 640≦I RI ≦799 set the periodicity M RI equal to 20 and the offset N OFFSET,RI equal to −I RI +640, and
if 800≦I RI ≦959 set the periodicity M RI equal to 40 and the offset N OFFSET,RI equal to −I RI +800.
6. The user equipment of claim 5 , wherein:
said user equipment is further operable to not report a RI if I RI =960.