Layer 1 and layer 2 channel state information rich reporting mechanisms

1. A method in a user equipment of reporting multi-beam channel state information, CSI, in uplink control information, UCI, the method including:

performing a first transmission in the UCI, the first transmission indicating a plurality of beam index pairs, (l k ,m k ), each beam index pair corresponding to a beam k; and

performing a second transmission in the UCI, the second transmission indicating at least one of a beam power, a beam rotation and a channel quality index, CQI.

2. The method of claim 1 , wherein a beam power p k of a beam k is a real number such that a cophasing factor c k can be expressed c k =c′ k p k , where |c k ′| 2 =1 and beam rotations r 1 and r 2 are real numbers such that beam directions for beam k, Δ 1,k and Δ 2,k can be expressed as Δ 1,k =Δ′ 1,k +r 1 and Δ′ 2,k =Δ′ 2,k +r 2 .

3. The method of claim 1 , further comprising:

generating a first periodicity CSI report corresponding to a plurality of beams and identifying a plurality of beam cophasing factors; and

transmitting the beam cophasing factors on an uplink transport channel, the uplink transport channel being produced using a medium access control, MAC, protocol.

4. The method of claim 1 , further comprising:

receiving signaling identifying a periodicity N pd with which a plurality of CSI reports should be transmitted;

determining at least a second periodicity H′·N pd , where H′ is an integer greater than zero;

transmitting a CQI report of a plurality of CQI reports in UCI in a subframe occurring once every N pd subframes unless a second periodicity CSI report is to be transmitted, wherein

the second periodicity CSI report includes at least one of a beam index i, the beam power, and the beam rotation, in UCI in in a subframe occurring once every H′·N pd subframes, wherein:

a beam power p i for a beam with index i is a real number such that cophasing factor cophasing factor c i can be expressed c i =c′ i p i , where |c i ′| 2 =1, and

a beam rotation r 1 or r 2 is a real number such that beam directions a beam rotation r 1 or r 2 is a real number such that beam directions Δ 1 and Δ 2 can be expressed Δ 1 =Δ′ 1 +r 1 and Δ 2 =Δ′ 2 +r 2 ; and

if the second periodicity CSI report ( 28 ) is to be transmitted, transmitting the second periodicity CSI report once every H′·N pd subframes.

5. The method of claim 1 , wherein: each beam is a k th beam, d(k), that comprises a set of complex numbers and has index pair (l k ,m k ), each element of the set of complex numbers being characterized by at least one complex phase shift such that:

d n (k)=d i (k)α i,n e j2π(pΔ 1,k +qΔ 2,k ) ;

d n (k), and d i (k) are i th and n th elements of d(k), respectively;

α i,n is a real number corresponding to the i th and n th elements of d(k);

p and q are integers; and

beam directions Δ 1,k and Δ 2,k are real numbers corresponding to beams with index pair (l k , m k ) that determine the complex phase shifts e j2πΔ 1,k and e j2πΔ 2,k respectively; and

each beam cophasing coefficient is a complex number c k for d(k) that is used to adjust the phase of the i th element of d(k) according to c k d i (k).

6. The method of claim 1 , further comprising generating a third periodicity CSI report ( 28 ) corresponding to a first subframe, the CSI report ( 28 ) including indications of at least one of a recommended precoder, a channel quality indicator (CQI), a rank indicator (RI), and a CSI-RS resource indicator (CRI).

7. The method of claim 6 , further comprising:

determining a second subframe in which a user equipment may transmit the CSI report;

if the user equipment receives a grant allowing it to transmit in the second subframe, transmitting the CSI report in an uplink transport channel in the second subframe; and

otherwise, transmitting the CSI report in the uplink transport channel in a third subframe after the second subframe, wherein the user equipment receives a grant allowing it to transmit in the third subframe.

8. The method of claim 1 , further comprising:

calculating a channel quality metric in a first subframe;

generating a CSI report corresponding to the first subframe; and

if the channel quality metric meets a reporting criterion, transmitting the CSI report in an uplink transport channel in a second subframe, the second subframe being after the first subframe.

9. The method of claim 1 , further comprising successfully decoding one of a downlink control channel and downlink shared transport channel (DL-SCH) in a first subframe, where one of downlink channel information, DCI, in the downlink control channel and the DL-SCH indicate that the user equipment should report CSI.

10. A user equipment for reporting multi-beam channel state information, CSI, in uplink control information, UCI, the user equipment including:

processing circuitry configured to:

indicate a plurality of beam index pairs, (l k ,m k ), in the UCI in a first transmission, each beam index pair corresponding to a beam k; and

indicate at least one of a beam power, a beam rotation and a channel quality index, CQI, in the UCI in a second transmission; and

a transceiver configured to transmit the first and second transmission.

11. The user equipment of claim 10 , wherein a beam power p k of a beam k is a real number such that a cophasing factor c k can be expressed c k =c′ k p k , where |c′ k | 2 =1, and beam rotations r 1 and r 2 are real numbers such that beam directions for beam k, Δ 1,k and Δ 2,k can be expressed as Δ 1,k =Δ′ 1,k +r 1 and Δ′ 2,k =Δ′ 2,k +r 2 .

12. The user equipment of claim 10 , wherein the processing circuitry is further configured to:

generate a CSI report corresponding to a plurality of beams and identifying a plurality of beam cophasing factors; and

transmit the beam cophasing factors on an uplink transport channel, the uplink transport channel being produced using a medium access control, MAC, protocol.

13. The user equipment of claim 10 , wherein: each beam is a k th beam, d(k), that comprises a set of complex numbers and has index pair (l k ,m k ), each element of the set of complex numbers being characterized by at least one complex phase shift such that:

d n (k)=d i (k)α i,n e j2π(pΔ 1,k +qΔ 2,k ) ;

d n (k), and d i (k) are i th and n th elements of d(k), respectively;

α i,n is a real number corresponding to the i th and n th elements of d(k);

p and q are integers; and

beam directions Δ 1,k and Δ 2,k are real numbers corresponding to beams with index pair (l k , m k ) that determine the complex phase shifts e j2πΔ 1,k and e j2πΔ 2,k respectively; and

each beam cophasing coefficient is a complex number c k for d(k) that is used to adjust the phase of the i th element of d(k) according to c k d i (k).

14. The user equipment of claim 10 , wherein:

the transceiver is further configured to:

receive signaling identifying a periodicity N pd with which a plurality of CSI reports should be transmitted;

transmit a CQI report of a plurality of CQI reports in UCI in a subframe occurring once every N pd subframes unless a second periodicity CSI report is to be transmitted, wherein:

the second periodicity CSI report includes at least one of the beam index i, the beam power, and the beam rotation, in UCI in in a subframe occurring once every H′·N pd subframes, wherein:

a beam power p i for a beam with index i is a real number such that cophasing factor c i can be expressed c i =c′ i p i , where |c i ′| 2 =1, and

a beam rotation r 1 or r 2 is a real number such that beam directions Δ 1 and Δ 2 can be expressed Δ 1 =Δ′ 1 +r 1 and Δ 2 =Δ′ 2 +r 2 ; and

if the second periodicity CSI report is to be transmitted, transmit the second CSI report once every H′·N pd subframes.

15. The user equipment of claim 10 , wherein the processing circuitry is further configured to generate a CSI report corresponding to a first subframe, the CSI report including indications of at least one of a recommended precoder, a channel quality indicator (COI), a rank indicator (RI), and a CSI-RS resource indicator (CRI).

16. The user equipment of claim 15 , wherein the processing circuitry is further configured to:

determine a second subframe in which the user equipment may transmit the CSI report; and

the transceiver configured to;

if the user equipment receives a grant allowing it to transmit in the second subframe, transmit the CSI report in an uplink transport channel in the second subframe; and

otherwise, transmit the CSI report in the uplink transport channel in a third subframe after the second subframe, wherein the user equipment receives a grant allowing it to transmit in the third subframe.

17. The user equipment of claim 10 , wherein the processing circuitry is further configured to:

calculate a channel quality metric in a first subframe;

generate a CSI report corresponding to the first subframe; and

the transceiver further configured to, if the channel quality metric meets a reporting criterion, transmit the CSI report in an uplink transport channel in a second subframe, the second subframe being after the first subframe.

18. The user equipment of claim 10 , wherein the processing circuitry is further configured to decode one of a downlink control channel and downlink shared transport channel, DL-SCH, in a first subframe, where one of downlink control information, DCI, in the downlink control channel and the DL-SCH indicate that the user equipment should report CSI.

19. A base station comprising:

processing circuitry configured to:

instruct a user equipment to calculate and transmit channel station information, CSI, reports;

receive, in a first transmission of the UCI, an indication of a plurality of beam index pairs, (l k ,m k ), each beam index pair corresponding to a beam k; and

receive, in a second transmission of the UCI, an indication of at least one of a beam power, a beam rotation and a channel quality index, CQI.

20. The base station of claim 19 , wherein a beam power p k of a beam k is a real number such that a cophasing factor c k can be expressed c k =c′ k p k , where |c′ k | 2 =1, and beam rotations r 1 and r 2 are real numbers such that beam directions for beam k, Δ 1,k and Δ 2,k can be expressed as Δ 1,k =Δ′ 1,k +r 1 and Δ 2,k =Δ′ 2,k +r 2 .