5G NR PHY Calculators

Five interactive RF & PHY calculators for 5G NR engineers

Change any input and results update instantly.

§1 Link Budget

Cascaded EIRP → path loss → RSL → SNR → link margin. Four propagation models (Free-Space, UMa/UMi NLOS, Indoor OHB). Live max-range solve.

§2 PRACH Root Seq

TS 38.211 Ncs table lookup for long (L_RA=839) and short (L_RA=139) sequences. Root count, ZCZ, max cell radius, preamble bar chart.

§3 Cell Throughput

PRB × symbols × MCS × layers → peak Mbps. Supports 5G NR MCS table (TS 38.214), numerology, overhead, MIMO layers.

§4 NTN Doppler

LEO/MEO satellite Doppler shift: altitude, velocity, elevation angle, carrier frequency → max f_d, chirp rate, timing pre-compensation.

§5 Beamforming Gain

ULA/UPA array factor pattern. N elements, spacing, steering angle → gain dBi, HPBW, first null, grating-lobe warning, canvas polar plot.

Enter system parameters and the cascade table updates live. The final Link Margin row turns green (>3 dB), amber (0–3 dB), or red (<0 dB). The max-range field shows the farthest distance at which the link still closes with the chosen margins.

Parameters LIVE

Tx Power (P_tx) dBm Tx Antenna Gain dBi Tx Cable Loss dB

Distance m Carrier Frequency MHz Propagation Model

Rx Antenna Gain dBi Rx Noise Figure dB System Bandwidth MHz

Required SNR (MCS target) dB Shadow Fading Margin dB Interference Margin dB

EIRP

37.05

dBm

Path Loss

—

dB

RSL

—

dBm

Rx SNR

—

dB

Link Margin

—

dB

Status

—

Calculation Cascade

Parameter	Formula	Value

Maximum Range

Solve for max distance where Link Margin = 0

Max Range

—

m

Max Allowed PL

—

dB

Max range is computed by solving the selected path loss model for PL_max = EIRP + G_rx − N_th − Required SNR − Margins. The inverse formula is solved numerically (bisection) for UMa/UMi/Indoor or analytically for Free Space.

Select a PRACH format, restriction type, and zeroCorrelationZoneConfig index. The calculator performs the TS 38.211 table lookup, computes preambles per root sequence, required root sequences out of 64 preambles, ZCZ length, and estimated maximum cell radius.

Parameters LIVE

PRACH Format Restriction Type

zeroCorrelationZoneConfig Index 0–15

5

Cell Radius Target km — for coverage check

5 km

L_RA

839

sequence length

N_cs

38

cyclic shift

ZCZ Length

37

chips

Root Sequences

3

needed for 64 preambles

Max Cell Radius

—

km

Coverage

OK

Preamble Distribution Across Root Sequences

Each colour block represents one root sequence. 64 preambles total.

Ncs Lookup Reference TS 38.211 §6.3.3.1

zeroCorrelationZoneConfig	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15

Coverage warning: The selected Ncs provides a maximum cell radius smaller than the target. Increase zeroCorrelationZoneConfig to a larger index for wider coverage, or reduce the cell radius target.

Rule: When N_cs = 0, the entire ZC sequence is used as a single root; all 64 preambles are obtained by cyclic shifts of one root (valid only for very small cells where no guard interval is needed for ranging). For N_cs > 0, preambles_per_root = floor(L_RA / Ncs) and root_sequences_needed = ceil(64 / preambles_per_root).

Peak DL/UL throughput from the 3GPP TS 38.306 §4.1.2 formula. Adjust numerology, bandwidth, MIMO layers and overhead to see how each parameter drives peak capacity.

Numerology μ Channel BW TDD Pattern UE Scaling Factor DL MIMO Layers 4 MCS Index (0–28) 27 64QAM DMRS Symbols (OH) 2 PDCCH Symbols (OH) 1 CSI-RS (1 sym OH)

Peak DL Throughput

—

Gbps

Peak UL Throughput

—

Gbps

Parameter	DL Value	UL Value
—

3GPP reference: 100 MHz / 4 layers / MCS 27 (910/1024) / μ=1 / DDDSUUDDDD / DMRS=2 / PDCCH=1 → DL ≈ 1.65 Gbps TS 38.306 §4.1.2

Non-Terrestrial Network (LEO satellite) Doppler shift, propagation delay and coherence time. Orbital mechanics: circular orbit — v = √(GM / (R_E + h)). Doppler along line-of-sight varies with satellite elevation angle.

Altitude h (km) 600 km Elevation θ_el 45 ° UE Velocity (km/h) 0 km/h Carrier Frequency f_c

Orbital Velocity

—km/s

Max Doppler Shift

—kHz

Doppler Spread (2×f_d)

—kHz

Coherence Time

—ms

One-Way Delay

—ms

Round-Trip Delay

—ms

TA Pre-comp. Needed

—ms

UE Doppler Component

—Hz

Doppler Shift vs Elevation Angle (selected altitude & frequency)

NTN Timing Advance note: O-RAN split 7-2x NTN requires uplink TA pre-compensation equal to 2 × (one-way propagation delay) to meet T2a windows. For a 600 km LEO at 45° elevation: one-way ≈ 3.3 ms → TA pre-compensation ≈ 6.6 ms. This is orders of magnitude larger than the nominal T2a_max_up of 196 μs (μ=1), requiring NTN-specific scheduler extensions (3GPP Rel-17 TS 38.300 §9.2.6).

Interactive ULA / UPA array factor pattern with live canvas rendering. Steering angle drives the array factor in real time. Element pattern follows 3GPP TR 38.901 §7.3 (A_max=30 dB, φ_3dB=65°).

Elements N 8 d/λ spacing 0.50 Steering angle θ (°) 0 ° Element pattern

Dual polarization (+3 dB)

N1 (horiz) 8 N2 (vert) 4 d_h/λ 0.50 d_v/λ 0.50 Azimuth φ (°) 0 ° Elevation θ (°) 0 ° Element pattern

Dual polarization (+3 dB)

Peak Array Gain
— dB

3 dB Beamwidth

— °

First Null (from boresight)

— °

Total Elements (incl. pol)

—

Array Factor (dB, normalized) vs Angle — live

Tx Power per port (dBm) EIRP = P_tx + G_array + G_elem = — dBm