Cell specific sounding reference signal sub-frame configuration
View Patent ↗A method of wireless communication including a plurality of fixed base stations and a plurality of mobile user equipment with each base station 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 cells may have differing sounding reference signal sub-frame configurations. There are numerous manners to encode the transmitted information.
1. A method of wireless communication including a plurality of fixed base stations and a plurality of mobile user equipment comprising the steps of:
each base station transmitting to any user equipment within a corresponding cell a sounding reference signal sub-frame configuration indicating sub-frames when sounding is permitted using jointly coding periodicity T SFC and offset Δ SFC , wherein differing base stations may transmit differing sounding reference signal sub-frame configurations;
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 including
maintaining a sub-frame count C SFC , and
sounding only if Δ SFC =(C SFC ) mod T SFC .
2. The method of claim 1 , wherein:
said step of jointly coding said periodicity T SFC and said offset Δ SFC codes in 4 bits suitable for use in time division duplex systems as follows:
Decimal
Binary
T SFC
Δ SFC
0
00000
1
0
1
00001
5
1
2
00010
5
2
3
00011
5
3
4
00100
5
4
5
00101
10
1
6
00110
10
2
7
00111
10
3
8
01000
10
4
9
01001
10
6
10
01010
10
7
11
01011
10
8
12
01100
10
9
13
01101
20
1
14
01110
20
2
15
01111
20
3
16
10000
20
4
17
10001
20
6
18
10010
20
7
19
10011
20
8
20
10100
20
9
21
10101
40
1
22
10110
40
2
23
10111
40
3
24
11000
40
4
25
11001
40
6
26
11010
40
7
27
11011
40
8
28
11100
40
9
29
11101
Reserved
Reserved
30
11110
Reserved
Reserved
31
11111
Inf.
0
where: codings 29, binary 11101 and decimal 30, binary 11110 are reserved; and coding decimal 31 and binary 11111 indicates no SRS thus T SFC is infinite and Δ SFC is 0.
3. The method of claim 1 , wherein:
said step of jointly coding said periodicity T SFC and said offset Δ SFC codes in 4 bits suitable for use in time division multiplex systems as follows:
Decimal
Binary
T SFC
Δ SFC
0
0000
5
{1}
1
0001
5
{1, 2}
2
0010
5
{1, 3}
3
0011
5
{1, 4}
4
0100
5
{1, 2, 3}
5
0101
5
{1, 2, 4}
6
0110
5
{1, 3, 4}
7
0111
5
{1, 2, 3, 4}
8
1000
10
{1, 2, 6}
9
1001
10
{1, 3, 6}
10
1010
10
{1, 6, 7}
11
1011
20
{1, 2, 6, 11, 16}
12
1100
20
{1, 3, 6, 11, 16}
13
1101
20
{1, 6, 7, 11, 16}
14
1110
Inf.
NA
15
1111
reserved
reserved
where: coding decimal 14, binary 1110 indicates no SRS thus T SFC is infinite and Δ SFC is thus not applicable (NA); and coding 15, binary 1111 is reserved.
4. The method of claim 1 , wherein:
said step of jointly coding said periodicity T SFC and said offset Δ SFC codes in 4 bits suitable for use in time division multiplex systems as follows:
Decimal
Binary
T SFC
Δ SFC
0
0000
5
{1}
1
0001
5
{1, 2}
2
0010
5
{1, 3}
3
0011
5
{1, 4}
4
0100
5
{1, 2, 3}
5
0101
5
{1, 2, 4}
6
0110
5
{1, 3, 4}
7
0111
5
{1, 2, 3, 4}
8
1000
10
{1, 2, 6}
9
1001
10
{1, 3, 6}
10
1010
10
{1, 6, 7}
11
1011
10
{1, 2, 6, 7}
12
1100
10
{1, 3, 6, 8}
13
1101
10
{1, 4, 6, 9}
14
1110
Inf
NA
15
1111
reserved
reserved
where: coding decimal 14, binary 1110 indicates no SRS thus T SFC is infinite and Δ SFC is thus not applicable (NA); and coding 15, binary 1111 is reserved.
5. The method of claim 1 , 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 increasing 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 0 if is N=0 or N=31,
N−N[k]+1 if N−N[k]+1≦4 and N−N[k]+2 otherwise.
6. The method of claim 5 , wherein:
said monotonically increasing array of k elements T SFC (k) consists of {1, 5, 10, 20, 40, Inf.} ms, where k is 6; and
said switch-point numbers are 0, 1, 5, 13, 21, 29 and infinity.