What is prach planning in LTE?

What is prach planning in LTE?

PRACH Planning in LTE PRACH Planning Principle •In LTE it is necessary the radio planner to selects the preamble format for each cell based on maximum estimated cell range. Typical preamble format will be ‘Preamble Format 0’, allowing for cell sizes up to 15km. Other preamble formats allow for larger cell ranges.

What is prach frequency offset in LTE?

PRACH Frequency Offset

System Bandwidth Resource Block Offset Range Resource Block Offset Default Value
5 MHz 0 to 19 0
10 MHz 0 to 44 0
15 MHz 0 to 69 0
20 MHz 0 to 94 0

What is Rach root sequence?

The RACH Root. Sequence index indicates the first root sequence number that is to be used by. a UE for preamble generation. 25. This formula is applicable when Ncs unrestricted set and preamble format.

What is prach used for?

Physical Random Access Channel (PRACH) is an uplink channel used by UE for connection request purpose. PRACH is used to carry the RACH transport channel data.

What is prach configuration index?

As you see, PRACH Configuration Index determines the Preamble Format to be used. For example, if PRACH Configuration Index is 10 as shown in the following example, the preamble format 0 is used. The you may ask ‘Who determines PRACH Configuration index?’ .

What is prach format?

PRACH Preamble Frequency Structure The ratio of the normal uplink subcarrier spacing to PRACH subcarrier spacing, K, is K=12 for formats 0–3 and K=2 for format 4. The PRACH is designed to fit in the same bandwidth as 6 RBs of normal uplink transmission. For example, 72 subcarriers at 15,000 Hz spacing is 1.08 MHz.

What is 5G prach?

Abstract: Similar to previous mobile communication systems, random access (RA) procedure in fifth generation of mobile communication (5G) is used to achieve the uplink synchronization between user equipment (UE) and next generation Node B (gNB) based on the detection of preambles in Physical Random Access Channel ( …

What is the difference between Rach and prach?

RACH is transport-layer channel; the corresponding physical-layer channel is PRACH.

What is prach preamble in 5G?

A preamble is send by UE to gNB over PRACH channel to obtain the UL synchronization. Similar to LTE, in 5G NR there are 64 preambles defined in each time-frequency PRACH occasion. The preamble consists of two parts cyclic prefix (CP) and Preamble Sequence.

What is the purpose of prach?

PRACH is used to carry random access preamble from UE towards gNB (i.e. 5G NR base station). It helps gNB to adjust uplink timings of the UE in addition to other parameters. Zadoff chu sequences are used to generate 5G NR random access preamble similar to LTE technology.

What is PRACH format?

What is PRACH configuration index?

The PRACH Configuration Index (prachConfIndex) parameter specifies the index, which informs UE of which frame number and which subframe number (SFN) within the frame has PRACH resources. RACH root sequence’s planning is dependent on PRACH cyclic shift.