122 ETSI ES 201 980 V4.1.2 (2017-04)
NOTE: This is equivalent to the complex value Us,k multiplied by - 1 for odd values of s.
8.4.3Time references
8.4.3.0Introduction
These cells are located in the first OFDM symbol of each transmission frame, i.e. s = 0 .
The time reference cells are mainly used for performing ambiguity resolution since guard time correlation provides a fast and frequency insensitive estimation of time of arrival with a periodicity of one symbol. They are used for determining the first symbol of a transmission frame. They can also be used for frequency-offset estimation.
8.4.3.1Cell positions and phases
Tables 53 to 57 define the phases of the time reference cells, and the phases of the frequency reference cells for the first symbol of the transmission frame.
ϑ1024[0, k] is the phase index in 1 024ths of a cycle.
Table 53: Phase of time reference cells for robustness mode A
Carrier index, k |
Phase index, ϑ1024[0, k] |
17 |
973 |
18* |
205 |
19 |
717 |
21 |
264 |
28 |
357 |
29 |
357 |
32 |
952 |
33 |
440 |
39 |
856 |
40 |
88 |
41 |
88 |
53 |
68 |
54* |
836 |
55 |
836 |
56 |
836 |
60 |
1 008 |
61 |
1 008 |
63 |
752 |
71 |
215 |
72* |
215 |
73 |
727 |
NOTE: |
Carrier numbers marked with an asterisk "*" also |
|
serve as frequency references (see clause 8.4.2.1); |
|
the definitions of phase index are consistent. |
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123 ETSI ES 201 980 V4.1.2 (2017-04)
Table 54: Phase of time reference cells for robustness mode B
Carrier index k |
Phase index, ϑ1024[0, k] |
14 |
304 |
16* |
331 |
18 |
108 |
20 |
620 |
24 |
192 |
26 |
704 |
32 |
44 |
36 |
432 |
42 |
588 |
44 |
844 |
48* |
651 |
49 |
651 |
50 |
651 |
54 |
460 |
56 |
460 |
62 |
944 |
64* |
555 |
66 |
940 |
68 |
428 |
NOTE: |
Carrier numbers marked with an asterisk "*" also serve |
|
as frequency references (see clause 8.4.2.1); the |
|
definitions of phase index are consistent. |
Table 55: Phase of time reference cells for robustness mode C
Carrier index k |
Phase index, ϑ1024[0, k] |
|
|
8 |
722 |
10 |
466 |
11* |
214 |
12 |
214 |
14 |
479 |
16 |
516 |
18 |
260 |
22 |
577 |
24 |
662 |
28 |
3 |
30 |
771 |
32 |
392 |
33* |
392 |
36 |
37 |
38 |
37 |
42 |
474 |
44* |
242 |
45 |
242 |
46 |
754 |
NOTE: |
Carrier numbers marked with an asterisk "*" also serve |
|
as frequency references (see clause 8.4.2.1); the |
|
definitions of phase index are consistent. |
ETSI
124 ETSI ES 201 980 V4.1.2 (2017-04)
Table 56: Phase of time reference cells for robustness mode D
Carrier index k |
Phase index, ϑ1024[0, k] |
|
|
5 |
636 |
6 |
124 |
7* |
788 |
8 |
788 |
9 |
200 |
11 |
688 |
12 |
152 |
14 |
920 |
15 |
920 |
17 |
644 |
18 |
388 |
20 |
652 |
21* |
1 014 |
23 |
176 |
24 |
176 |
26 |
752 |
27 |
496 |
28* |
332 |
29 |
432 |
30 |
964 |
32 |
452 |
NOTE: |
Carrier numbers marked with an asterisk "*" also |
|
serve as frequency references (see clause 8.4.2.1); |
|
the definitions of phase index are consistent. |
Table 57: Phase of time reference cells for robustness mode E
Carrier index, k |
Phase index, ϑ1024[0, k] |
-80 |
219 |
-79 |
475 |
-77 |
987 |
-53 |
652 |
-52 |
652 |
-51 |
140 |
-32 |
819 |
-31 |
819 |
12 |
907 |
13 |
907 |
14 |
651 |
21 |
903 |
22 |
391 |
23 |
903 |
40 |
203 |
41 |
203 |
42 |
203 |
67 |
797 |
68 |
29 |
79 |
508 |
80 |
508 |
ETSI