5.7 Physical random access channel
36.2113GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical channels and modulationRelease 17TS
5.7.1 Time and frequency structure
The physical layer random access preamble, illustrated in Figure 5.7.1-1, consists of a cyclic prefix of length
and a sequence part of length
. The parameter values are listed in Table 5.7.1-1 and depend on the frame structure and the random access configuration. Higher layers control the preamble format.
Figure 5.7.1-1: Random access preamble format
Table 5.7.1-1: Random access preamble parameters
|
Preamble format |
|
|
|
0 |
|
|
|
1 |
|
|
|
2 |
|
|
|
3 |
|
|
|
4 (see Note) |
|
|
|
NOTE: Frame structure type 2 and special subframe configurations with UpPTS lengths |
||
and 
only assuming that the number of additional SC-FDMA symbols in UpPTS X in Table 4.2-1 is 0.The transmission of a random access preamble, if triggered by the MAC layer, is restricted to certain time and frequency resources. These resources are enumerated in increasing order of the subframe number within the radio frame and the physical resource blocks in the frequency domain such that index 0 correspond to the lowest numbered physical resource block and subframe within the radio frame. PRACH resources within the radio frame are indicated by a PRACH configuration index, where the indexing is in the order of appearance in Table 5.7.1-2 and Table 5.7.1-4.
For non-BL/CE UEs there are up to two PRACH configurations in a cell. The first PRACH configuration is configured by higher layers with a PRACH configuration index (prach-ConfigurationIndex) and a PRACH frequency offset 
(prach-FrequencyOffset). The second PRACH configuration (if any) is configured by higher layers with a PRACH configuration index (prach-ConfigurationIndexHighSpeed) and a PRACH frequency offset 
(prach-FrequencyOffsetHighSpeed).
For BL/CE UEs, for each PRACH coverage enhancement level, there is a PRACH configuration configured by higher layers with a PRACH configuration index (prach-ConfigurationIndex), a PRACH frequency offset 
(prach-FrequencyOffset), a number of PRACH repetitions per attempt 
(numRepetitionPerPreambleAttempt) and optionally a PRACH starting subframe periodicity 
(prach-StartingSubframe). PRACH of preamble format 0-3 is transmitted 
times, whereas PRACH of preamble format 4 is transmitted one time only.
For BL/CE UEs and for each PRACH coverage enhancement level, if frequency hopping is enabled for a PRACH configuration by the higher-layer parameter prach-HoppingConfig, the value of the parameter 
depends on the SFN and the PRACH configuration index and is given by
– In case the PRACH configuration index is such that a PRACH resource occurs in every radio frame when calculated as below from Table 5.7.1-2 or Table 5.7.1-4,
– otherwise
where 
is the system frame number corresponding to the first subframe for each PRACH repetition, 
corresponds to a cell-specific higher-layer parameter prach-HoppingOffset. If frequency hopping is not enabled for the PRACH configuration then 
.
For frame structure type 1 with preamble format 0-3, for each of the PRACH configurations there is at most one random access resource per subframe.
Table 5.7.1-2 lists the preamble formats according to Table 5.7.1-1 and the subframes in which random access preamble transmission is allowed for a given configuration in frame structure type 1. The start of the random access preamble shall be aligned with the start of the corresponding uplink subframe at the UE assuming 
, where 
is defined in clause 8.1. For PRACH configurations 0, 1, 2, 15, 16, 17, 18, 31, 32, 33, 34, 47, 48, 49, 50 and 63 the UE may for handover purposes assume an absolute value of the relative time difference between radio frame 
in the current cell and the target cell of less than 
.
The first physical resource block 
allocated to the PRACH opportunity considered for preamble formats 0, 1, 2 and 3 is defined as 
.
Table 5.7.1-2: Frame structure type 1 random access configuration for preamble formats 0-3
|
PRACH Configuration Index |
Preamble |
System frame number |
Subframe number |
PRACH Configuration Index |
Preamble |
System frame number |
Subframe number |
|
0 |
0 |
Even |
1 |
32 |
2 |
Even |
1 |
|
1 |
0 |
Even |
4 |
33 |
2 |
Even |
4 |
|
2 |
0 |
Even |
7 |
34 |
2 |
Even |
7 |
|
3 |
0 |
Any |
1 |
35 |
2 |
Any |
1 |
|
4 |
0 |
Any |
4 |
36 |
2 |
Any |
4 |
|
5 |
0 |
Any |
7 |
37 |
2 |
Any |
7 |
|
6 |
0 |
Any |
1, 6 |
38 |
2 |
Any |
1, 6 |
|
7 |
0 |
Any |
2 ,7 |
39 |
2 |
Any |
2 ,7 |
|
8 |
0 |
Any |
3, 8 |
40 |
2 |
Any |
3, 8 |
|
9 |
0 |
Any |
1, 4, 7 |
41 |
2 |
Any |
1, 4, 7 |
|
10 |
0 |
Any |
2, 5, 8 |
42 |
2 |
Any |
2, 5, 8 |
|
11 |
0 |
Any |
3, 6, 9 |
43 |
2 |
Any |
3, 6, 9 |
|
12 |
0 |
Any |
0, 2, 4, 6, 8 |
44 |
2 |
Any |
0, 2, 4, 6, 8 |
|
13 |
0 |
Any |
1, 3, 5, 7, 9 |
45 |
2 |
Any |
1, 3, 5, 7, 9 |
|
14 |
0 |
Any |
0, 1, 2, 3, 4, 5, 6, 7, 8, 9 |
46 |
N/A |
N/A |
N/A |
|
15 |
0 |
Even |
9 |
47 |
2 |
Even |
9 |
|
16 |
1 |
Even |
1 |
48 |
3 |
Even |
1 |
|
17 |
1 |
Even |
4 |
49 |
3 |
Even |
4 |
|
18 |
1 |
Even |
7 |
50 |
3 |
Even |
7 |
|
19 |
1 |
Any |
1 |
51 |
3 |
Any |
1 |
|
20 |
1 |
Any |
4 |
52 |
3 |
Any |
4 |
|
21 |
1 |
Any |
7 |
53 |
3 |
Any |
7 |
|
22 |
1 |
Any |
1, 6 |
54 |
3 |
Any |
1, 6 |
|
23 |
1 |
Any |
2 ,7 |
55 |
3 |
Any |
2 ,7 |
|
24 |
1 |
Any |
3, 8 |
56 |
3 |
Any |
3, 8 |
|
25 |
1 |
Any |
1, 4, 7 |
57 |
3 |
Any |
1, 4, 7 |
|
26 |
1 |
Any |
2, 5, 8 |
58 |
3 |
Any |
2, 5, 8 |
|
27 |
1 |
Any |
3, 6, 9 |
59 |
3 |
Any |
3, 6, 9 |
|
28 |
1 |
Any |
0, 2, 4, 6, 8 |
60 |
N/A |
N/A |
N/A |
|
29 |
1 |
Any |
1, 3, 5, 7, 9 |
61 |
N/A |
N/A |
N/A |
|
30 |
N/A |
N/A |
N/A |
62 |
N/A |
N/A |
N/A |
|
31 |
1 |
Even |
9 |
63 |
3 |
Even |
9 |
For frame structure type 2 with preamble formats 0-4, for each of the PRACH configurations there might be multiple random access resources in an UL subframe (or UpPTS for preamble format 4) depending on the UL/DL configuration [see table 4.2-2]. Table 5.7.1-3 lists PRACH configurations allowed for frame structure type 2 where the configuration index corresponds to a certain combination of preamble format, PRACH density value, 
and version index, 
.
For frame structure type 2 with PRACH configuration indices 0, 1, 2, 20, 21, 22, 30, 31, 32, 40, 41, 42, 48, 49, 50, or with PRACH configuration indices 51, 53, 54, 55, 56, 57 in UL/DL configuration 3, 4, 5, the UE may for handover purposes assume an absolute value of the relative time difference between radio frame 
in the current cell and the target cell is less than 
.
Table 5.7.1-3: Frame structure type 2 random access configurations for preamble formats 0-4
|
PRACH Index |
Preamble |
Density Per 10 ms
|
Version |
PRACH Index |
Preamble |
Density Per 10 ms
|
Version |
|
0 |
0 |
0.5 |
0 |
32 |
2 |
0.5 |
2 |
|
1 |
0 |
0.5 |
1 |
33 |
2 |
1 |
0 |
|
2 |
0 |
0.5 |
2 |
34 |
2 |
1 |
1 |
|
3 |
0 |
1 |
0 |
35 |
2 |
2 |
0 |
|
4 |
0 |
1 |
1 |
36 |
2 |
3 |
0 |
|
5 |
0 |
1 |
2 |
37 |
2 |
4 |
0 |
|
6 |
0 |
2 |
0 |
38 |
2 |
5 |
0 |
|
7 |
0 |
2 |
1 |
39 |
2 |
6 |
0 |
|
8 |
0 |
2 |
2 |
40 |
3 |
0.5 |
0 |
|
9 |
0 |
3 |
0 |
41 |
3 |
0.5 |
1 |
|
10 |
0 |
3 |
1 |
42 |
3 |
0.5 |
2 |
|
11 |
0 |
3 |
2 |
43 |
3 |
1 |
0 |
|
12 |
0 |
4 |
0 |
44 |
3 |
1 |
1 |
|
13 |
0 |
4 |
1 |
45 |
3 |
2 |
0 |
|
14 |
0 |
4 |
2 |
46 |
3 |
3 |
0 |
|
15 |
0 |
5 |
0 |
47 |
3 |
4 |
0 |
|
16 |
0 |
5 |
1 |
48 |
4 |
0.5 |
0 |
|
17 |
0 |
5 |
2 |
49 |
4 |
0.5 |
1 |
|
18 |
0 |
6 |
0 |
50 |
4 |
0.5 |
2 |
|
19 |
0 |
6 |
1 |
51 |
4 |
1 |
0 |
|
20 |
1 |
0.5 |
0 |
52 |
4 |
1 |
1 |
|
21 |
1 |
0.5 |
1 |
53 |
4 |
2 |
0 |
|
22 |
1 |
0.5 |
2 |
54 |
4 |
3 |
0 |
|
23 |
1 |
1 |
0 |
55 |
4 |
4 |
0 |
|
24 |
1 |
1 |
1 |
56 |
4 |
5 |
0 |
|
25 |
1 |
2 |
0 |
57 |
4 |
6 |
0 |
|
26 |
1 |
3 |
0 |
58 |
N/A |
N/A |
N/A |
|
27 |
1 |
4 |
0 |
59 |
N/A |
N/A |
N/A |
|
28 |
1 |
5 |
0 |
60 |
N/A |
N/A |
N/A |
|
29 |
1 |
6 |
0 |
61 |
N/A |
N/A |
N/A |
|
30 |
2 |
0.5 |
0 |
62 |
N/A |
N/A |
N/A |
|
31 |
2 |
0.5 |
1 |
63 |
N/A |
N/A |
N/A |
Table 5.7.1-4 lists the mapping to physical resources for the different random access opportunities needed for a certain PRACH density value, 
. Each quadruple of the format 
indicates the location of a specific random access resource, where 
is a frequency resource index within the considered time instance, 
indicates whether the resource is reoccurring in all radio frames, in even radio frames, or in odd radio frames, respectively, 
indicates whether the random access resource is located in first half frame or in second half frame, respectively, and where 
is the uplink subframe number where the preamble starts, counting from 0 at the first uplink subframe between 2 consecutive downlink-to-uplink switch points, with the exception of preamble format 4 where 
is denoted as (*). The start of the random access preamble formats 0-3 shall be aligned with the start of the corresponding uplink subframe at the UE assuming 
and the random access preamble format 4 shall start 
before the end of the UpPTS at the UE, where the UpPTS is referenced to the UE’s uplink frame timing assuming
.
The random access opportunities for each PRACH configuration shall be allocated in time first and then in frequency if and only if time multiplexing is not sufficient to hold all opportunities of a PRACH configuration needed for a certain density value 
without overlap in time. For preamble format 0-3, the frequency multiplexing shall be done according to
where 
is the number of uplink resource blocks, 
is the first physical resource block allocated to the PRACH opportunity considered and where 
is the first physical resource block available for PRACH.
For preamble format 4, the frequency multiplexing shall be done according to
where
is the system frame number and where
is the number of DL to UL switch points within the radio frame.
For BL/CE UEs, only a subset of the subframes allowed for preamble transmission are allowed as starting subframes for the 
repetitions. The allowed starting subframes for a PRACH configuration are determined as follows:
– Enumerate the subframes that are allowed for preamble transmission for the PRACH configuration as 
where 
and 
correspond to the two subframes allowed for preamble transmission with the smallest and the largest absolute subframe number 
, respectively.
– If a PRACH starting subframe periodicity 
is not provided by higher layers, the periodicity of the allowed starting subframes in terms of subframes allowed for preamble transmission is 
. The allowed starting subframes defined over 
are given by 
where 
– If a PRACH starting subframe periodicity 
is provided by higher layers, it indicates the periodicity of the allowed starting subframes in terms of subframes allowed for preamble transmission. The allowed starting subframes defined over 
are given by 
where 
– No starting subframe defined over 
such that 
is allowed.
Each random access preamble occupies a bandwidth corresponding to 6 consecutive resource blocks for both frame structures.
Table 5.7.1-4: Frame structure type 2 random access preamble mapping in time and frequency
|
PRACH configuration Index (See Table 5.7.1-3) |
UL/DL configuration (See Table 4.2-2) |
||||||
|---|---|---|---|---|---|---|---|
|
0 |
1 |
2 |
3 |
4 |
5 |
6 |
|
|
0 |
(0,1,0,2) |
(0,1,0,1) |
(0,1,0,0) |
(0,1,0,2) |
(0,1,0,1) |
(0,1,0,0) |
(0,1,0,2) |
|
1 |
(0,2,0,2) |
(0,2,0,1) |
(0,2,0,0) |
(0,2,0,2) |
(0,2,0,1) |
(0,2,0,0) |
(0,2,0,2) |
|
2 |
(0,1,1,2) |
(0,1,1,1) |
(0,1,1,0) |
(0,1,0,1) |
(0,1,0,0) |
N/A |
(0,1,1,1) |
|
3 |
(0,0,0,2) |
(0,0,0,1) |
(0,0,0,0) |
(0,0,0,2) |
(0,0,0,1) |
(0,0,0,0) |
(0,0,0,2) |
|
4 |
(0,0,1,2) |
(0,0,1,1) |
(0,0,1,0) |
(0,0,0,1) |
(0,0,0,0) |
N/A |
(0,0,1,1) |
|
5 |
(0,0,0,1) |
(0,0,0,0) |
N/A |
(0,0,0,0) |
N/A |
N/A |
(0,0,0,1) |
|
6 |
(0,0,0,2) (0,0,1,2) |
(0,0,0,1) (0,0,1,1) |
(0,0,0,0) (0,0,1,0) |
(0,0,0,1) (0,0,0,2) |
(0,0,0,0) (0,0,0,1) |
(0,0,0,0) (1,0,0,0) |
(0,0,0,2) (0,0,1,1) |
|
7 |
(0,0,0,1) (0,0,1,1) |
(0,0,0,0) (0,0,1,0) |
N/A |
(0,0,0,0) (0,0,0,2) |
N/A |
N/A |
(0,0,0,1) (0,0,1,0) |
|
8 |
(0,0,0,0) (0,0,1,0) |
N/A |
N/A |
(0,0,0,0) (0,0,0,1) |
N/A |
N/A |
(0,0,0,0) (0,0,1,1) |
|
9 |
(0,0,0,1) (0,0,0,2) (0,0,1,2) |
(0,0,0,0) (0,0,0,1) (0,0,1,1) |
(0,0,0,0) (0,0,1,0) (1,0,0,0) |
(0,0,0,0) (0,0,0,1) (0,0,0,2) |
(0,0,0,0) (0,0,0,1) (1,0,0,1) |
(0,0,0,0) (1,0,0,0) (2,0,0,0) |
(0,0,0,1) (0,0,0,2) (0,0,1,1) |
|
10 |
(0,0,0,0) (0,0,1,0) (0,0,1,1) |
(0,0,0,1) (0,0,1,0) (0,0,1,1) |
(0,0,0,0) (0,0,1,0) (1,0,1,0) |
N/A |
(0,0,0,0) (0,0,0,1) (1,0,0,0) |
N/A |
(0,0,0,0) (0,0,0,2) (0,0,1,0) |
|
11 |
N/A |
(0,0,0,0) (0,0,0,1) (0,0,1,0) |
N/A |
N/A |
N/A |
N/A |
(0,0,0,1) (0,0,1,0) (0,0,1,1) |
|
12 |
(0,0,0,1) (0,0,0,2) (0,0,1,1) (0,0,1,2) |
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) |
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (1,0,0,2) |
(0,0,0,0) (0,0,0,1) (1,0,0,0) (1,0,0,1) |
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) |
(0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) |
|
13 |
(0,0,0,0) (0,0,0,2) (0,0,1,0) (0,0,1,2) |
N/A |
N/A |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (1,0,0,1) |
N/A |
N/A |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,1) |
|
14 |
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) |
N/A |
N/A |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (1,0,0,0) |
N/A |
N/A |
(0,0,0,0) (0,0,0,2) (0,0,1,0) (0,0,1,1) |
|
15 |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,1) (0,0,1,2) |
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,0,1) |
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (2,0,0,0) |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (1,0,0,1) (1,0,0,2) |
(0,0,0,0) (0,0,0,1) (1,0,0,0) (1,0,0,1) (2,0,0,1) |
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (4,0,0,0) |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) |
|
16 |
(0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) (0,0,1,2) |
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,1,1) |
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (2,0,1,0) |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (1,0,0,0) (1,0,0,2) |
(0,0,0,0) (0,0,0,1) (1,0,0,0) (1,0,0,1) (2,0,0,0) |
N/A |
N/A |
|
17 |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,2) |
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,0,0) |
N/A |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (1,0,0,0) (1,0,0,1) |
N/A |
N/A |
N/A |
|
18 |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) (0,0,1,2) |
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,0,1) (1,0,1,1) |
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (2,0,0,0) (2,0,1,0) |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (1,0,0,0) (1,0,0,1) (1,0,0,2) |
(0,0,0,0) (0,0,0,1) (1,0,0,0) (1,0,0,1) (2,0,0,0) (2,0,0,1) |
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (4,0,0,0) (5,0,0,0) |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) (1,0,0,2) |
|
19 |
N/A |
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,0,0) (1,0,1,0) |
N/A |
N/A |
N/A |
N/A |
(0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) (1,0,1,1) |
|
20 / 30 |
(0,1,0,1) |
(0,1,0,0) |
N/A |
(0,1,0,1) |
(0,1,0,0) |
N/A |
(0,1,0,1) |
|
21 / 31 |
(0,2,0,1) |
(0,2,0,0) |
N/A |
(0,2,0,1) |
(0,2,0,0) |
N/A |
(0,2,0,1) |
|
22 / 32 |
(0,1,1,1) |
(0,1,1,0) |
N/A |
N/A |
N/A |
N/A |
(0,1,1,0) |
|
23 / 33 |
(0,0,0,1) |
(0,0,0,0) |
N/A |
(0,0,0,1) |
(0,0,0,0) |
N/A |
(0,0,0,1) |
|
24 / 34 |
(0,0,1,1) |
(0,0,1,0) |
N/A |
N/A |
N/A |
N/A |
(0,0,1,0) |
|
25 / 35 |
(0,0,0,1) (0,0,1,1) |
(0,0,0,0) (0,0,1,0) |
N/A |
(0,0,0,1) (1,0,0,1) |
(0,0,0,0) (1,0,0,0) |
N/A |
(0,0,0,1) (0,0,1,0) |
|
26 / 36 |
(0,0,0,1) (0,0,1,1) (1,0,0,1) |
(0,0,0,0) (0,0,1,0) (1,0,0,0) |
N/A |
(0,0,0,1) (1,0,0,1) (2,0,0,1) |
(0,0,0,0) (1,0,0,0) (2,0,0,0) |
N/A |
(0,0,0,1) (0,0,1,0) (1,0,0,1) |
|
27 / 37 |
(0,0,0,1) (0,0,1,1) (1,0,0,1) (1,0,1,1) |
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) |
N/A |
(0,0,0,1) (1,0,0,1) (2,0,0,1) (3,0,0,1) |
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) |
N/A |
(0,0,0,1) (0,0,1,0) (1,0,0,1) (1,0,1,0) |
|
28 / 38 |
(0,0,0,1) (0,0,1,1) (1,0,0,1) (1,0,1,1) (2,0,0,1) |
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (2,0,0,0) |
N/A |
(0,0,0,1) (1,0,0,1) (2,0,0,1) (3,0,0,1) (4,0,0,1) |
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (4,0,0,0) |
N/A |
(0,0,0,1) (0,0,1,0) (1,0,0,1) (1,0,1,0) (2,0,0,1) |
|
29 /39 |
(0,0,0,1) (0,0,1,1) (1,0,0,1) (1,0,1,1) (2,0,0,1) (2,0,1,1) |
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (2,0,0,0) (2,0,1,0) |
N/A |
(0,0,0,1) (1,0,0,1) (2,0,0,1) (3,0,0,1) (4,0,0,1) (5,0,0,1) |
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (4,0,0,0) (5,0,0,0) |
N/A |
(0,0,0,1) (0,0,1,0) (1,0,0,1) (1,0,1,0) (2,0,0,1) (2,0,1,0) |
|
40 |
(0,1,0,0) |
N/A |
N/A |
(0,1,0,0) |
N/A |
N/A |
(0,1,0,0) |
|
41 |
(0,2,0,0) |
N/A |
N/A |
(0,2,0,0) |
N/A |
N/A |
(0,2,0,0) |
|
42 |
(0,1,1,0) |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
|
43 |
(0,0,0,0) |
N/A |
N/A |
(0,0,0,0) |
N/A |
N/A |
(0,0,0,0) |
|
44 |
(0,0,1,0) |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
|
45 |
(0,0,0,0) (0,0,1,0) |
N/A |
N/A |
(0,0,0,0) (1,0,0,0) |
N/A |
N/A |
(0,0,0,0) (1,0,0,0) |
|
46 |
(0,0,0,0) (0,0,1,0) (1,0,0,0) |
N/A |
N/A |
(0,0,0,0) (1,0,0,0) (2,0,0,0) |
N/A |
N/A |
(0,0,0,0) (1,0,0,0) (2,0,0,0) |
|
47 |
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) |
N/A |
N/A |
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) |
N/A |
N/A |
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) |
|
48 |
(0,1,0,*) |
(0,1,0,*) |
(0,1,0,*) |
(0,1,0,*) |
(0,1,0,*) |
(0,1,0,*) |
(0,1,0,*) |
|
49 |
(0,2,0,*) |
(0,2,0,*) |
(0,2,0,*) |
(0,2,0,*) |
(0,2,0,*) |
(0,2,0,*) |
(0,2,0,*) |
|
50 |
(0,1,1,*) |
(0,1,1,*) |
(0,1,1,*) |
N/A |
N/A |
N/A |
(0,1,1,*) |
|
51 |
(0,0,0,*) |
(0,0,0,*) |
(0,0,0,*) |
(0,0,0,*) |
(0,0,0,*) |
(0,0,0,*) |
(0,0,0,*) |
|
52 |
(0,0,1,*) |
(0,0,1,*) |
(0,0,1,*) |
N/A |
N/A |
N/A |
(0,0,1,*) |
|
53 |
(0,0,0,*) (0,0,1,*) |
(0,0,0,*) (0,0,1,*) |
(0,0,0,*) (0,0,1,*) |
(0,0,0,*) (1,0,0,*) |
(0,0,0,*) (1,0,0,*) |
(0,0,0,*) (1,0,0,*) |
(0,0,0,*) (0,0,1,*) |
|
54 |
(0,0,0,*) (0,0,1,*) (1,0,0,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) |
|
55 |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) |
|
56 |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) |
|
57 |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (2,0,1,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (2,0,1,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (2,0,1,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) (5,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) (5,0,0,*) |
(0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) (5,0,0,*) |
(0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (2,0,1,*) |
|
58 |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
|
59 |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
|
60 |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
|
61 |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
|
62 |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
|
63 |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
|
NOTE: * UpPTS |
|||||||
5.7.2 Preamble sequence generation
The random access preambles are generated from Zadoff-Chu sequences with zero correlation zone, generated from one or several root Zadoff-Chu sequences. The network configures the set of preamble sequences the UE is allowed to use.
There are up to two sets of 64 preambles available in a cell where Set 1 corresponds to higher layer PRACH configuration using prach-ConfigurationIndex and prach-FrequencyOffset and Set 2, if configured, corresponds to higher layer PRACH configuration using prach-ConfigurationIndexHighSpeed and prach-FrequencyOffsetHighSpeed. The set of 64 preamble sequences in a cell is found by including first, in the order of increasing cyclic shift, all the available cyclic shifts of a root Zadoff-Chu sequence with the logical index rootSequenceIndexHighSpeed (for Set 2, if configured) or with the logical index RACH_ROOT_SEQUENCE (for Set 1), where both rootSequenceIndexHighSpeed (if configured) and RACH_ROOT_SEQUENCE are broadcasted as part of the System Information. Additional preamble sequences, in case 64 preambles cannot be generated from a single root Zadoff-Chu sequence, are obtained from the root sequences with the consecutive logical indexes until all the 64 sequences are found.
The logical root sequence order is cyclic: the logical index 0 is consecutive to 837. The relation between a logical root sequence index and physical root sequence index 
is given by Tables 5.7.2-4 and 5.7.2-5 for preamble formats 0 – 3 and 4, respectively.
The 
root Zadoff-Chu sequence is defined by
where the length 
of the Zadoff-Chu sequence is given by Table 5.7.2-1. From the 
root Zadoff-Chu sequence, random access preambles with zero correlation zones of length 
are defined by cyclic shifts according to
where the cyclic shift is given by
and 
is given by Tables 5.7.2-2 and 5.7.2-3 for preamble formats 0-3 and 4, respectively, where the higher-layer parameters zeroCorrelationZoneConfig and zeroCorrelationZoneConfigHighSpeed shall be used for PRACH preamble Set 1 and Set 2 (if configured), respectively. Restricted set type B shall be used for PRACH preamble Set 2 (if configured), and the parameter High-speed-flag provided by higher layers determines if unrestricted set or restricted set type A shall be used for PRACH preamble Set 1.
The variable 
is the cyclic shift corresponding to a Doppler shift of magnitude 
and is given by
where 
is the smallest non-negative integer that fulfils 
. The parameters for restricted sets of cyclic shifts depend on 
.
For restricted set type A and 
, the parameters are given by
For restricted set type A and 
, the parameters are given by
For restricted set type B and 
, the parameters are given by
For restricted set type B and 
, the parameters are given by
For restricted set type B and 
, the parameters are given by
For restricted set type B and 
, the parameters are given by
For restricted set type B and 
, the parameters are given by
For restricted set type B and 
, the parameters are given by
For all other values of 
, there are no cyclic shifts in the restricted set.
Table 5.7.2-1: Random access preamble sequence length
|
Preamble format |
|
|
0 – 3 |
839 |
|
4 |
139 |
Table 5.7.2-2: 
for preamble generation (preamble formats 0-3)
|
zeroCorrelationZoneConfig, |
|
||
|
Unrestricted set |
Restricted set type A |
Restricted set type B |
|
|
0 |
0 |
15 |
15 |
|
1 |
13 |
18 |
18 |
|
2 |
15 |
22 |
22 |
|
3 |
18 |
26 |
26 |
|
4 |
22 |
32 |
32 |
|
5 |
26 |
38 |
38 |
|
6 |
32 |
46 |
46 |
|
7 |
38 |
55 |
55 |
|
8 |
46 |
68 |
68 |
|
9 |
59 |
82 |
82 |
|
10 |
76 |
100 |
100 |
|
11 |
93 |
128 |
118 |
|
12 |
119 |
158 |
137 |
|
13 |
167 |
202 |
– |
|
14 |
279 |
237 |
– |
|
15 |
419 |
– |
– |
valueTable 5.7.2-3: 
for preamble generation (preamble format 4)
|
zeroCorrelationZoneConfig |
|
|
0 |
2 |
|
1 |
4 |
|
2 |
6 |
|
3 |
8 |
|
4 |
10 |
|
5 |
12 |
|
6 |
15 |
|
7 |
N/A |
|
8 |
N/A |
|
9 |
N/A |
|
10 |
N/A |
|
11 |
N/A |
|
12 |
N/A |
|
13 |
N/A |
|
14 |
N/A |
|
15 |
N/A |
valueTable 5.7.2-4: Root Zadoff-Chu sequence order for preamble formats 0 – 3
|
Logical root sequence number |
Physical root sequence number (in increasing order of the corresponding logical sequence number) |
|
0–23 |
129, 710, 140, 699, 120, 719, 210, 629, 168, 671, 84, 755, 105, 734, 93, 746, 70, 769, 60, 779 2, 837, 1, 838 |
|
24–29 |
56, 783, 112, 727, 148, 691 |
|
30–35 |
80, 759, 42, 797, 40, 799 |
|
36–41 |
35, 804, 73, 766, 146, 693 |
|
42–51 |
31, 808, 28, 811, 30, 809, 27, 812, 29, 810 |
|
52–63 |
24, 815, 48, 791, 68, 771, 74, 765, 178, 661, 136, 703 |
|
64–75 |
86, 753, 78, 761, 43, 796, 39, 800, 20, 819, 21, 818 |
|
76–89 |
95, 744, 202, 637, 190, 649, 181, 658, 137, 702, 125, 714, 151, 688 |
|
90–115 |
217, 622, 128, 711, 142, 697, 122, 717, 203, 636, 118, 721, 110, 729, 89, 750, 103, 736, 61, 778, 55, 784, 15, 824, 14, 825 |
|
116–135 |
12, 827, 23, 816, 34, 805, 37, 802, 46, 793, 207, 632, 179, 660, 145, 694, 130, 709, 223, 616 |
|
136–167 |
228, 611, 227, 612, 132, 707, 133, 706, 143, 696, 135, 704, 161, 678, 201, 638, 173, 666, 106, 733, 83, 756, 91, 748, 66, 773, 53, 786, 10, 829, 9, 830 |
|
168–203 |
7, 832, 8, 831, 16, 823, 47, 792, 64, 775, 57, 782, 104, 735, 101, 738, 108, 731, 208, 631, 184, 655, 197, 642, 191, 648, 121, 718, 141, 698, 149, 690, 216, 623, 218, 621 |
|
204–263 |
152, 687, 144, 695, 134, 705, 138, 701, 199, 640, 162, 677, 176, 663, 119, 720, 158, 681, 164, 675, 174, 665, 171, 668, 170, 669, 87, 752, 169, 670, 88, 751, 107, 732, 81, 758, 82, 757, 100, 739, 98, 741, 71, 768, 59, 780, 65, 774, 50, 789, 49, 790, 26, 813, 17, 822, 13, 826, 6, 833 |
|
264–327 |
5, 834, 33, 806, 51, 788, 75, 764, 99, 740, 96, 743, 97, 742, 166, 673, 172, 667, 175, 664, 187, 652, 163, 676, 185, 654, 200, 639, 114, 725, 189, 650, 115, 724, 194, 645, 195, 644, 192, 647, 182, 657, 157, 682, 156, 683, 211, 628, 154, 685, 123, 716, 139, 700, 212, 627, 153, 686, 213, 626, 215, 624, 150, 689 |
|
328–383 |
225, 614, 224, 615, 221, 618, 220, 619, 127, 712, 147, 692, 124, 715, 193, 646, 205, 634, 206, 633, 116, 723, 160, 679, 186, 653, 167, 672, 79, 760, 85, 754, 77, 762, 92, 747, 58, 781, 62, 777, 69, 770, 54, 785, 36, 803, 32, 807, 25, 814, 18, 821, 11, 828, 4, 835 |
|
384–455 |
3, 836, 19, 820, 22, 817, 41, 798, 38, 801, 44, 795, 52, 787, 45, 794, 63, 776, 67, 772, 72 767, 76, 763, 94, 745, 102, 737, 90, 749, 109, 730, 165, 674, 111, 728, 209, 630, 204, 635, 117, 722, 188, 651, 159, 680, 198, 641, 113, 726, 183, 656, 180, 659, 177, 662, 196, 643, 155, 684, 214, 625, 126, 713, 131, 708, 219, 620, 222, 617, 226, 613 |
|
456–513 |
230, 609, 232, 607, 262, 577, 252, 587, 418, 421, 416, 423, 413, 426, 411, 428, 376, 463, 395, 444, 283, 556, 285, 554, 379, 460, 390, 449, 363, 476, 384, 455, 388, 451, 386, 453, 361, 478, 387, 452, 360, 479, 310, 529, 354, 485, 328, 511, 315, 524, 337, 502, 349, 490, 335, 504, 324, 515 |
|
514–561 |
323, 516, 320, 519, 334, 505, 359, 480, 295, 544, 385, 454, 292, 547, 291, 548, 381, 458, 399, 440, 380, 459, 397, 442, 369, 470, 377, 462, 410, 429, 407, 432, 281, 558, 414, 425, 247, 592, 277, 562, 271, 568, 272, 567, 264, 575, 259, 580 |
|
562–629 |
237, 602, 239, 600, 244, 595, 243, 596, 275, 564, 278, 561, 250, 589, 246, 593, 417, 422, 248, 591, 394, 445, 393, 446, 370, 469, 365, 474, 300, 539, 299, 540, 364, 475, 362, 477, 298, 541, 312, 527, 313, 526, 314, 525, 353, 486, 352, 487, 343, 496, 327, 512, 350, 489, 326, 513, 319, 520, 332, 507, 333, 506, 348, 491, 347, 492, 322, 517 |
|
630–659 |
330, 509, 338, 501, 341, 498, 340, 499, 342, 497, 301, 538, 366, 473, 401, 438, 371, 468, 408, 431, 375, 464, 249, 590, 269, 570, 238, 601, 234, 605 |
|
660–707 |
257, 582, 273, 566, 255, 584, 254, 585, 245, 594, 251, 588, 412, 427, 372, 467, 282, 557, 403, 436, 396, 443, 392, 447, 391, 448, 382, 457, 389, 450, 294, 545, 297, 542, 311, 528, 344, 495, 345, 494, 318, 521, 331, 508, 325, 514, 321, 518 |
|
708–729 |
346, 493, 339, 500, 351, 488, 306, 533, 289, 550, 400, 439, 378, 461, 374, 465, 415, 424, 270, 569, 241, 598 |
|
730–751 |
231, 608, 260, 579, 268, 571, 276, 563, 409, 430, 398, 441, 290, 549, 304, 535, 308, 531, 358, 481, 316, 523 |
|
752–765 |
293, 546, 288, 551, 284, 555, 368, 471, 253, 586, 256, 583, 263, 576 |
|
766–777 |
242, 597, 274, 565, 402, 437, 383, 456, 357, 482, 329, 510 |
|
778–789 |
317, 522, 307, 532, 286, 553, 287, 552, 266, 573, 261, 578 |
|
790–795 |
236, 603, 303, 536, 356, 483 |
|
796–803 |
355, 484, 405, 434, 404, 435, 406, 433 |
|
804–809 |
235, 604, 267, 572, 302, 537 |
|
810–815 |
309, 530, 265, 574, 233, 606 |
|
816–819 |
367, 472, 296, 543 |
|
820–837 |
336, 503, 305, 534, 373, 466, 280, 559, 279, 560, 419, 420, 240, 599, 258, 581, 229, 610 |
Table 5.7.2-5: Root Zadoff-Chu sequence order for preamble format 4
|
Logical root sequence number |
Physical root sequence number (in increasing order of the corresponding logical sequence number) |
|||||||||||||||||||
|
0 – 19 |
1 |
138 |
2 |
137 |
3 |
136 |
4 |
135 |
5 |
134 |
6 |
133 |
7 |
132 |
8 |
131 |
9 |
130 |
10 |
129 |
|
20 – 39 |
11 |
128 |
12 |
127 |
13 |
126 |
14 |
125 |
15 |
124 |
16 |
123 |
17 |
122 |
18 |
121 |
19 |
120 |
20 |
119 |
|
40 – 59 |
21 |
118 |
22 |
117 |
23 |
116 |
24 |
115 |
25 |
114 |
26 |
113 |
27 |
112 |
28 |
111 |
29 |
110 |
30 |
109 |
|
60 – 79 |
31 |
108 |
32 |
107 |
33 |
106 |
34 |
105 |
35 |
104 |
36 |
103 |
37 |
102 |
38 |
101 |
39 |
100 |
40 |
99 |
|
80 – 99 |
41 |
98 |
42 |
97 |
43 |
96 |
44 |
95 |
45 |
94 |
46 |
93 |
47 |
92 |
48 |
91 |
49 |
90 |
50 |
89 |
|
100 – 119 |
51 |
88 |
52 |
87 |
53 |
86 |
54 |
85 |
55 |
84 |
56 |
83 |
57 |
82 |
58 |
81 |
59 |
80 |
60 |
79 |
|
120 – 137 |
61 |
78 |
62 |
77 |
63 |
76 |
64 |
75 |
65 |
74 |
66 |
73 |
67 |
72 |
68 |
71 |
69 |
70 |
– |
– |
|
138 – 837 |
N/A |
|||||||||||||||||||
5.7.3 Baseband signal generation
The time-continuous random access signal 
is defined by
where
, 
is an amplitude scaling factor in order to conform to the transmit power 
specified in clause 6.1 in TS 36.213 [4], and 
. The location in the frequency domain is controlled by the parameter 
is derived from clause 5.7.1. The factor 
accounts for the difference in subcarrier spacing between the random access preamble and uplink data transmission. The variable
, the subcarrier spacing for the random access preamble, and the variable
, a fixed offset determining the frequency-domain location of the random access preamble within the physical resource blocks, are both given by Table 5.7.3-1.
Table 5.7.3-1: Random access baseband parameters
|
Preamble format |
|
|
|
0 – 3 |
1250 Hz |
7 |
|
4 |
7500 Hz |
2 |
