NB-IoT NPRACH Measurement
R&S
®
CMW-KM300/-KS300
332
User Manual 1178.5689.02 ─ 06
The length of the CP depends on the preamble format (PF). There are two preamble
formats defined by 3GPP, format 0 and format 1. The symbol length is fixed.
Lengths are often defined in multiples of the basic time unit T
s
(1 T
s
= 1/30.72 MHz
≈
32.55 ns).
The following figure provides an overview.
Cyclic prefix
PF0: 2048 T
s
PF1: 8192 T
s
One symbol group
Symbol
8192 Ts
Symbol
8192 Ts
Symbol
8192 Ts
Symbol
8192 Ts
Symbol
8192 Ts
One preamble without repetitions (PF0: 5.6 ms, PF1: 6.4 ms)
Figure 4-3: Preamble structure in the time domain
The frequency domain covers 180 kHz and is divided into 48 subcarriers, each
3.75
kHz wide. The subcarriers are numbered from 0 to 47.
Preambles are transmitted on a single subcarrier with frequency hopping between the
symbol groups. The following figure shows an example for the transmission of a single
preamble.
Subcarriers
Time
Figure 4-4: Single preamble with frequency hopping between symbol groups
For more details, see 3GPP TS 36.211 section 10.1.6.1 "Time and frequency struc-
ture".
General Description
深圳德标仪器
135-1095-0799
