F.5 Window length

38.101-13GPPNRPart 1: Range 1 StandaloneRelease 17TSUser Equipment (UE) radio transmission and reception

F.5.1 Timing offset

As a result of using a cyclic prefix, there is a range of, which, at least in the case of perfect Tx signal quality, would give close to minimum error vector magnitude. As a first order approximation, that range should be equal to the length of the cyclic prefix. Any time domain windowing or FIR pulse shaping applied by the transmitter reduces the range within which the error vector is close to its minimum.

F.5.2 Window length

The window length W affects the measured EVM and is expressed as a function of the configured cyclic prefix length. In the case where equalization is present, as with frequency domain EVM computation, the effect of FIR is reduced. This is because the equalization can correct most of the linear distortion introduced by the FIR. However, the time domain windowing effect can’t be removed.

F.5.3 Window length for normal CP

Table F.5.3-1, F.5.3-2, F.5.3-3 below specify the EVM window length (W) for normal CP.

Table F.5.3-1: EVM window length for normal CP for NR, FR1, 15 kHz SCS

Channel Bandwidth (MHz)	FFT size	Cyclic prefix length for symbols 1‑6 and 8-13 in FFT samples	EVM window length W	Ratio of W to total CP length for symbols 1‑6 and 8-131 (%)
5	512	36	18	50
10	1024	72	36	50
15	1536	108	54	50
20	2048	144	72	50
25	2048	144	72	50
30	3072	216	108	50
40	4096	288	144	50
50	4096	288	144	50
NOTE 1: These percentages are informative and apply to a slot’s symbols 1 to 6 and 8 to 13. Symbols 0 and 7 have a longer CP and therefore a lower percentage.

Table F.5.3-2: EVM window length for normal CP for NR, FR1, 30 kHz SCS

Channel Bandwidth (MHz)	FFT size	Cyclic prefix length for symbols 1‑13 in FFT samples	EVM window length W	Ratio of W to total CP length for symbols 1‑131 (%)
5	256	18	9	50
10	512	36	18	50
15	768	54	27	50
20	1024	72	36	50
25	1024	72	36	50
30	1536	108	54	50
40	2048	144	72	50
50	2048	144	72	50
60	3072	216	108	50
70	3072	216	108	50
80	4096	288	144	50
90	4096	288	144	50
100	4096	288	144	50
NOTE 1: These percentages are informative and apply to a slot’s symbols 1 through 13. Symbol 0 has a longer CP and therefore a lower percentage.

Table F.5.3-3: EVM window length for normal CP for NR (60 kHz SCS)

Channel Bandwidth (MHz)	FFT size	Cyclic prefix length for symbols in FFT samples	EVM window length W	Ratio of W to total CP length 1 (%)
10	256	18	9	50
15	384	27	14	50
20	512	36	18	50
25	512	36	18	50
30	768	54	27	50
40	1024	72	36	50
50	1024	72	36	50
60	1536	108	54	50
70	1536	108	54	50
80	2048	144	72	50
90	2048	144	72	50
100	2048	144	72	50
NOTE 1: These percentages are informative and apply to all OFDM symbols within subframe except for symbol 0 of slot 0 and slot 2. Symbol 0 of slot 0 and slot 2 may have a longer CP and therefore a lower percentage.

F.5.4 Window length for Extended CP

Table F.5.4-1 below specifies the EVM window length (W) for extended CP. The number of CP samples excluded from the EVM window is the same as for normal CP length.

Table F.5.4-1: EVM window length for extended CP for NR, FR1, 60 kHz SCS

Channel Bandwidth (MHz)	FFT size	Cyclic prefix length in FFT samples	EVM window length W	Ratio of W to total CP length1 (%)
10	256	64	54	84.4
15	384	96	80	83.3
20	512	128	106	82.8
25	512	128	110	85.9
30	768	192	164	85.4
40	1024	256	220	85.9
50	1024	256	220	85.9
60	1536	384	330	85.9
70	1536	384	330	85.9
80	2048	512	440	85.9
90	2048	512	440	85.9
100	2048	512	440	85.9
NOTE 1: These percentages are informative.

F.5.5 Window length for PRACH

The table below specifies the EVM window length for PRACH preamble formats for L_RA= 839 and .

Table F.5.5-1 EVM window length for PRACH formats for L_RA= 839

Preamble format	Cyclic prefix length NCP	Nominal FFT size1	EVM window length W in FFT samples	Ratio of W to CP2
0	3168	24576	2307	72.8%
1	21024	24576	20163	95.9%
2	4688	24576	3827	81.6%
3	3168	6144	2952	93.2%
NOTE 1: The use of other FFT sizes is possible as long as appropriate scaling of the window length is applied NOTE 2: These percentages are informative

The table below specifies the EVM window length for PRACH preamble formats for L_RA= 139 and where.

Table F.5.5-2 EVM window length for PRACH formats for L_RA= 139

Preamble format	Cyclic prefix length NCP	Nominal FFT size1	EVM window length W in FFT samples	Ratio of W to CP2
A1	2882–	20482–	1442–	50.0%
A2	5762–	20482–	4322–	75.0%
A3	8642–	20482–	7202–	83.3%
B1	2162–	20482–	722–	33.3%
B2	3602–	20482–	2162–	60.0%
B3	5042–	20482–	3602–	71.4%
B4	9362–	20482–	7922–	84.6%
C0	12402–	20482–	10962–	88.4%
C2	20482–	20482–	19042–	93.0%
NOTE 1: The use of other FFT sizes is possible as long as appropriate scaling of the window length is applied NOTE 2: These percentages are informative