Sounding Reference Signal User Equipment Specific Sub-Frame Configuration

• US 20090274076A1
• Filed: 03/26/2009
• Published: 11/05/2009
• Est. Priority Date: 04/29/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Shen, Zukang, Muharemovic, Tarik
• Granted Patent: US 9,363,054 B2
• Time in Patent Office: Days
• US Class Current: 370/280
• CPC Class Codes: H04L 5/0039 Frequency-contiguous, i.e. with no allocation of frequencies for one user or terminal between the frequencies allocated to another
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/1263 Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows

Abstract

A method of wireless communication including a plurality of fixed basestations and a plurality of mobile user equipment with each basestation transmitting to any user equipment within a corresponding cell a sounding reference signal sub-frame configuration indicating sub-frames when sounding is permitted. Each user equipment recognizes the sounding reference signal sub-frame configuration and sounds only at permitted sub-frames. Differing user equipment may have differing sounding reference signal sub-frame configurations. There are numerous manners to encode the transmitted information.

Claims

1. A method of wireless communication including a plurality of fixed basestations and a plurality of mobile user equipment comprising the steps of:

each basestation transmitting to each user equipment within a corresponding cell a sounding reference signal sub-frame configuration indicating sub-frames when sounding is permitted;

each user equipment within said corresponding cell recognizing said sounding reference signal sub-frame configuration; and

each user equipment sounding only at sub-frames when sounding is permitted according to said recognized sounding reference signal sub-frame configuration.

2. The method of claim 1, wherein:

said step of each basestation transmitting a sounding reference signal sub-frame configuration wherein said basestation may transmit differing sounding reference signal sub-frame configurations to differing user equipment.

3. The method of claim 1, wherein:

said step of each basestation transmitting a sounding reference signal sub-frame configuration includes

transmitting a periodicity T_SFC, and

transmitting an offset Δ

_SFC;

said step of each user equipment sounding only at sub-frames when sounding is permitted includes

maintaining a sub-frame count C_SFC, and

sounding only if Δ

_SFC=(C_SFC)mod T_SFC.

4. The method of claim 3, wherein:

said steps of transmitting said periodicity T_SFC and transmitting said offset Δ

_SFC includes separately coding said periodicity T_SFC and said offset Δ

_SFC.

5. The method of claim 3, wherein:

said steps of transmitting said periodicity T_SFC and transmitting said offset Δ

_SFC includes jointly coding said periodicity T_SFC and said offset Δ

_SFC.

6. The method of claim 5, wherein:

said step of jointly coding said periodicity T_SFC and said offset Δ

_SFC codes in 5 bits as follows;

Decimal Binary T_SFC Δ

_SFC 0 00000 1 0 1 00001 2 0 2 00010 2 1 3 00011 5 0 4 00100 5 1 5 00101 5 2 6 00110 5 3 7 00111 5 4 8 01000 10 0 9 01001 10 1 10 01010 10 2 11 01011 10 3 12 01100 10 4 13 01101 10 5 14 01110 10 6 15 01111 10 7 16 10000 10 8 17 10001 10 9 18 10010 20 0 19 10011 20 1 20 10100 20 2 21 10101 20 3 22 10110 20 4 23 10111 20 5 24 11000 20 6 25 11001 20 7 26 11010 20 8 27 11011 20 9 28 11100 20 10 29 11101 20 11 30 11110 20 12 31 11111 Inf. 0

where;

coding of decimal 31 indicates no SRS thus T_SFC is infinite, Δ

_SFC is meaningless and not applicable (NA).

7. The method of claim 5, wherein:

said step of jointly coding said periodicity T_SFC and said offset Δ

_SFC codes in 4 bits suitable for use in frequency division duplex systems as follows;

Decimal Binary T_SFC Δ

_SFC 0 0000 1 0 1 0001 2 0 2 0010 2 1 3 0011 5 0 4 0100 5 1 5 0101 5 2 6 0110 5 3 7 0111 10 0 8 1000 10 1 9 1001 10 2 10 1010 10 3 11 1011 20 0 12 1100 20 1 13 1101 20 2 14 1110 20 3 15 1111 Inf. 0

where;

coding of decimal 15 indicates no SRS thus T_SFC is infinite, Δ

_SFC is meaningless and not applicable (NA).

8. The method of claim 5, wherein:

said step of jointly coding said periodicity T_SFC and said offset Δ

_SFC codes in 3 bits as follows;

Decimal Binary T_SFC Δ

_SFC 0 000  

1 0 1 001 10 0 2 010 10 1 3 011 10 2 4 100 20 0 5 101 20 1 6 110 20 2 7 111 20 3 8 000 Inf. 0

where;

coding of decimal 8 indicates no SRS thus T_SFC is infinite, Δ

_SFC is meaningless and not applicable (NA).

9. The method of claim 5, wherein:

said step of jointly coding said periodicity T_SFC and said offset Δ

_SFC codes in 3 bits as follows;

Decimal Binary T_SFC Δ

_SFC 0 000 5 0 1 001 5 0 2 010 5 1 3 011 10 2 4 100 10 0 5 101 10 1 6 110 20 2 7 111 20 3 8 000 20 0

10. The method of claim 5, wherein:

said step of jointly coding said periodicity T_SFC and said offset Δ

_SFC. includes

determining a set of K possible periodicities T_SFC,

disposing said set of possible periodicities T_SFC in a monotonically increasting array of K elements T_SFC(k),

recessively defining a set of switch points N where N(0)=0 and N(k+1)=N(k)+T_SFC(k), and

transmitting an configuration index N; and

said step of recognizing said sounding reference signal sub-frame configuration includes

finding a unique index k for which N(k)≦

N<

N(k+1),

determining the periodicity T_SFC to be T_SFC(k), and

determining the offset Δ

_SFC to be N−

N(k).

11. The method of claim 1, wherein:

said step of each basestation transmitting a sounding reference signal sub-frame configuration wherein said basestation transmits via broadcast (SIB).

12. The method of claim 1, wherein:

said step of each basestation transmitting a sounding reference signal sub-frame configuration wherein said basestation transmits via radio resource control (RRC).

13. The method of claim 1, wherein:

said step of each basestation transmitting a sounding reference signal sub-frame configuration wherein said basestation transmits via downlink (DL) signaling.

14. The method of claim 1, wherein:

each basestation and each UE operate according to a Evolved Universal Terrestrial Radio Access time division duplex frame structure where each sub-frame may carry two sounding reference signals;

said step of each basestation transmitting a sounding reference signal sub-frame configuration includes transmitting which orthogonal frequency division multiplexing symbol to employ in sounding;

said step of each user equipment within recognizing said sounding reference signal sub-frame configuration includes recognizing which orthogonal frequency division multiplexing symbol to employ in sounding; and

each user equipment sounding only at sub-frames when sounding is permitted including sounding using said recognized orthogonal frequency division multiplexing symbol.