BLE Waveform Generation
SkillDev toolsGenerate Bluetooth Low Energy (BLE) PHY waveforms. Read BEFORE writing any BLE waveform code to avoid hallucinating API patterns. Covers bleWaveformGenerator, bleIdealReceiver, bleCTEIQSample, bleAngleEstimate, bluetoothTestWaveform for LE1M/LE2M/LE500K/LE125K. Bluetooth Toolbox R2022a+.
Available today. Use it from your connected AI after setup.
No other account needed.
Connect ahel once, and every AI you use reads what you have installed.
Then ask your AI: use the BLE Waveform Generation skill
What this skill tells your AI
The instructions your AI receives, as published by matlab/matlab-agentic-toolkit in skills-catalog/wireless-communications/matlab-generate-ble-waveform/SKILL.md and read by ahel’s review.
Routing
| Intent | Cues | Pattern |
|---|---|---|
| Basic generation | "generate", "waveform" | Single-Mode |
| Compare modes | "compare", "all modes" | All-Mode |
| Direction finding | "CTE", "AoA", "AoD" | CTE |
| RF-PHY compliance | "compliance", "RF-PHY" | RF-PHY Test |
| Coexistence | "WLAN", "interference" | WLAN Coexistence |
| TX measurements | "PAPR", "OBW", "power" | TX Measurements |
| Localization | "RSSI", "beacon", "distance" | RSSI Localization |
| BER/receiver | "BER", "noise", "sensitivity" | BER Simulation |
| Multi-packet | "burst", "IFS" | Multi-Packet |
| Spectrum | "spectrum", "spectral mask" | Spectral Analysis |
| Whitening | "whitening", "scrambling" | Whitening Comparison |
| Impairments | "CFO", "practical", "realistic" | End-to-End |
Default (ambiguous request): LE1M, 37-byte payload, channel 37.
When To Use
Use this skill when the user asks to generate, simulate, or analyze BLE PHY-layer waveforms — including mode comparisons, CTE/direction finding, RF-PHY compliance testing, BER simulations, TX measurements, WLAN coexistence, or RSSI localization. Applies to any task involving bleWaveformGenerator, bleIdealReceiver, bleCTEIQSample, bleAngleEstimate, or bluetoothTestWaveform.
When Not To Use
- BR/EDR (Classic Bluetooth) → use
bluetoothWaveformGenerator(covered by a separate BR/EDR skill) - Channel Sounding (CS) → use
bleCSWaveform(bleCSConfig)(R2024b+); CS has its own ranging/distance-measurement pipeline and is not part of PHY waveform generation - Network-level simulation → use
bluetoothLENodefor link-layer/network modeling - Path loss modeling → use
bluetoothPathLossfor propagation/channel modeling
PHY Modes
| Mode | symbolRate | Data Rate | Coding | Duration (37 B) |
|---|---|---|---|---|
"LE1M" | 1e6 | 1 Mbps | None | ~336 us |
"LE2M" | 2e6 | 2 Mbps | None | ~172 us |
"LE500K" | 1e6 | 500 kbps | FEC S=2 | ~974 us |
"LE125K" | 1e6 | 125 kbps | FEC S=8 | ~2768 us |
References
For detailed guidance beyond what's in this file, see:
- functionalAPI.md — Full API reference for bleWaveformGenerator Name-Value pairs
- phy-modes-and-timing.md — Detailed timing calculations per PHY mode
- cte-direction-finding.md — CTE pipeline: generation, IQ sampling, constraints
- direction-finding.md — AoA/AoD angle estimation with bleAngleEstimate
- rfphy-compliance-testing.md — RF-PHY test waveform patterns and config
- transmitter-measurements.md — OBW, PAPR, power measurement patterns
- practical-receiver-simulation.md — BER simulation and impaired receiver
- wlan-coexistence.md — WLAN interference and coexistence scenarios
- rssi-localization.md — RSSI beacon and distance estimation patterns
- data-whitening.md — Whitening on/off comparison and internals
Parameters (bleWaveformGenerator)
| Param | Default | Range |
|---|---|---|
Mode | "LE1M" | LE1M, LE2M, LE500K, LE125K |
ChannelIndex | 37 | 0-39 |
SamplesPerSymbol | 8 | >=1 (use >=4 for plots) |
WhitenStatus | "On" | On, Off |
DFPacketType | "Disabled" | Disabled, ConnectionCTE, ConnectionlessCTE |
AccessAddress | adv default | 32-bit binary col vector |
ModulationIndex | 0.5 | [0.45, 0.55] |
PulseLength | 1 | [1, 4] |
Core Recipe
messageBits = randi([0 1], payloadLenBytes*8, 1);
waveform = bleWaveformGenerator(messageBits, ...
Mode=phyMode, SamplesPerSymbol=sps, ...
ChannelIndex=ch, WhitenStatus="On");
symbolRate = 1e6 + 1e6*(phyMode=="LE2M");
fs = symbolRate * sps;
Patterns
All-Mode Comparison
phyModes = ["LE1M","LE2M","LE500K","LE125K"];
sps = 8;
messageBits = randi([0 1], 37*8, 1);
figure; tl = tiledlayout(4,2,TileSpacing="compact",Padding="compact");
title(tl,"BLE - All PHY Modes")
for idx = 1:4
wf = bleWaveformGenerator(messageBits, ...
Mode=phyModes(idx), SamplesPerSymbol=sps, ChannelIndex=37, WhitenStatus="On");
sr = 1e6 + 1e6*(phyModes(idx)=="LE2M");
fs = sr*sps; t = (0:length(wf)-1)/fs*1e6;
nexttile; plot(t,real(wf),t,imag(wf))
xlabel("Time (\mus)"); ylabel("Amplitude"); title(phyModes(idx)+" - IQ")
legend("I","Q"); grid on; xlim([0 min(80,t(end))])
nexttile; N=length(wf); f=(-N/2:N/2-1)*(fs/N)/1e6;
plot(f, 20*log10(abs(fftshift(fft(wf)))/N+eps))
xlabel("Frequency (MHz)"); ylabel("dB"); title(phyModes(idx)+" - Spectrum")
grid on; xlim([-3 3]); ylim([-80 0])
end
Multi-Packet Burst (T_IFS = 150 us)
sps = 8; fs = 1e6*sps;
messageBits = randi([0 1], 37*8, 1);
ifsGap = complex(zeros(round(150e-6*fs), 1));
burst = complex(zeros(0,1));
for pkt = 1:3
wf = bleWaveformGenerator(messageBits, Mode="LE1M", SamplesPerSymbol=sps, ChannelIndex=37);
burst = [burst; wf; ifsGap]; %#ok<AGROW>
end
Round-Trip Decode
messageBits = randi([0 1], 37*8, 1); sps = 8;
wf = bleWaveformGenerator(messageBits, Mode="LE1M", SamplesPerSymbol=sps, ChannelIndex=37, WhitenStatus="On");
rxBits = bleIdealReceiver(wf, Mode="LE1M", SamplesPerSymbol=sps, ChannelIndex=37, WhitenStatus="On");
assert(isequal(rxBits, messageBits))
Data Channel + Custom Access Address
accessAddr = randi([0 1], 32, 1);
wf = bleWaveformGenerator(randi([0 1],27*8,1), ...
Mode="LE2M", SamplesPerSymbol=8, ChannelIndex=9, ...
AccessAddress=accessAddr, WhitenStatus="On");
fs = 2e6 * 8;
CTE Generation
messageBits = randi([0 1], 20*8, 1); sps = 8; fs = 1e6*sps;
wf_noCTE = bleWaveformGenerator(messageBits, Mode="LE1M", ...
SamplesPerSymbol=sps, ChannelIndex=10, WhitenStatus="On");
wf_conn = bleWaveformGenerator(messageBits, Mode="LE1M", ...
SamplesPerSymbol=sps, ChannelIndex=10, WhitenStatus="On", DFPacketType="ConnectionCTE");
wf_cless = bleWaveformGenerator(messageBits, Mode="LE1M", ...
SamplesPerSymbol=sps, ChannelIndex=10, WhitenStatus="On", DFPacketType="ConnectionlessCTE");
% CTE appends unmodulated constant tone for antenna switching (typ. 72-216 us)
cteDelta_conn_us = (length(wf_conn) - length(wf_noCTE)) / fs * 1e6;
cteDelta_cless_us = (length(wf_cless) - length(wf_noCTE)) / fs * 1e6;
CTE Full Pipeline (Tx → Rx → Angle)
pduHex = '02049B03270102030405'; % 10-byte PDU (>=6 bytes needed for >=11 IQ samples)
pdu = int2bit(hex2dec(reshape(pduHex, 2, [])'), 8, false);
pdu = pdu(:);
cfgCRC = crcConfig(Polynomial="z^24+z^10+z^9+z^6+z^4+z^3+z+1", ...
InitialConditions=int2bit(hex2dec('555551'),24), DirectMethod=true);
pduCRC = crcGenerate(pdu, cfgCRC);
txWf = bleWaveformGenerator(pduCRC, ChannelIndex=36, DFPacketType="ConnectionlessCTE");
[~, ~, iqSamples] = bleIdealReceiver(txWf, ChannelIndex=36, ...
DFPacketType="ConnectionlessCTE", SlotDuration=2);
cfgAngle = bleAngleEstimateConfig;
cfgAngle.ArraySize = 4; cfgAngle.SlotDuration = 2; cfgAngle.SwitchingPattern = [1 2 3 4];
angle = bleAngleEstimate(iqSamples, cfgAngle);
Alternative (R2022a+): iqSamples = bleCTEIQSample(cteSamples, Mode="LE1M", SlotDuration=2);
BER Simulation
messageBits = randi([0 1], 100*8, 1); sps = 8; phyMode = "LE1M";
snrValues = 0:4:20; berResults = zeros(size(snrValues));
for idx = 1:length(snrValues)
wf = bleWaveformGenerator(messageBits, Mode=phyMode, SamplesPerSymbol=sps, ChannelIndex=5, WhitenStatus="On");
sigPower = mean(abs(wf).^2);
rxWf = awgn(wf, snrValues(idx), 10*log10(sigPower));
rxBits = bleIdealReceiver(rxWf, Mode=phyMode, SamplesPerSymbol=sps, ChannelIndex=5, WhitenStatus="On");
n = min(length(messageBits), length(rxBits));
berResults(idx) = sum(messageBits(1:n) ~= double(rxBits(1:n))) / n;
end
semilogy(snrValues, berResults, "-o"); xlabel("SNR (dB)"); ylabel("BER"); grid on
bleIdealReceiver returns int8 — cast with double(). For Eb/No conversion: snr = convertSNR(EbNo,"ebno","snr",SamplesPerSymbol=sps).
RF-PHY Test Waveform
cfg = bluetoothTestWaveformConfig;
cfg.Mode = "LE1M"; cfg.PayloadLength = 37;
cfg.PacketType = "Disabled"; cfg.ModulationIndex = 0.5;
testWf = bluetoothTestWaveform(cfg);
rfCfg = bluetoothRFPHYTestConfig;
rfCfg.Test = "Output power"; rfCfg.Mode = "LE1M";
rfCfg.PayloadLength = 37; rfCfg.OutputPower = 0; rfCfg.CenterFrequency = "Mid";
WLAN Coexistence
sps = 8; fs = 1e6*sps;
bleWf = bleWaveformGenerator(randi([0 1],37*8,1), Mode="LE1M", SamplesPerSymbol=sps, ChannelIndex=37, WhitenStatus="On");
t = (0:length(bleWf)-1)'/fs;
wlanInterferer = 0.1*complex(randn(length(bleWf),1),randn(length(bleWf),1)) .* exp(1j*2*pi*3e6*t);
combined = bleWf + wlanInterferer;
CIR_dB = 10*log10(mean(abs(bleWf).^2) / mean(abs(wlanInterferer).^2));
TX Measurements (Power, OBW, PAPR)
sps = 8; wf = bleWaveformGenerator(randi([0 1],255*8,1), Mode="LE1M", ...
SamplesPerSymbol=sps, ChannelIndex=37, WhitenStatus="On", ModulationIndex=0.5);
fs = 1e6*sps; N = length(wf);
avgPower_dBm = 10*log10(mean(abs(wf).^2)) + 30;
spec = abs(fftshift(fft(wf))).^2; cumP = cumsum(spec)/sum(spec);
f = (-N/2:N/2-1)*(fs/N);
occBW_MHz = (f(find(cumP>=0.995,1)) - f(find(cumP>=0.005,1))) / 1e6;
papr_dB = 10*log10(max(abs(wf).^2) / mean(abs(wf).^2));
Whitening Comparison
bits = randi([0 1], 37*8, 1); sps = 8;
wfOn = bleWaveformGenerator(bits, Mode="LE1M", SamplesPerSymbol=sps, ChannelIndex=37, WhitenStatus="On");
wfOff = bleWaveformGenerator(bits, Mode="LE1M", SamplesPerSymbol=sps, ChannelIndex=37, WhitenStatus="Off");
Advertising PDU (ADV_IND)
cfgAdv = bleLLAdvertisingChannelPDUConfig;
cfgAdv.PDUType = "Advertising indication";
cfgAdv.AdvertiserAddress = "A1B2C3D4E5F6";
cfgAdv.AdvertiserAddressType = "Random";
cfgAdv.AdvertisingData = "0201060709546573744245020A00";
pduBits = bleLLAdvertisingChannelPDU(cfgAdv);
wf = bleWaveformGenerator(pduBits, Mode="LE1M", SamplesPerSymbol=8, ChannelIndex=37);
PDUType values: "Advertising indication", "Scan request", "Scan response", "Connection indication", "Advertising direct indication", "Advertising non connectable indication".
Addresses: 12-char hex string (no colons). AdvertisingData: hex string (length-type-value AD structs).
Data Channel PDU
cfgData = bleLLDataChannelPDUConfig;
cfgData.LLID = "Data (start fragment/complete)";
cfgData.SequenceNumber = 1;
cfgData.NESN = 0;
cfgData.MoreData = false;
payload = dec2hex(randi([0 255], 50, 1))'; % 50-byte hex payload
payload = reshape(payload', 1, []);
pduBits = bleLLDataChannelPDU(cfgData, payload);
wf = bleWaveformGenerator(pduBits, Mode="LE2M", SamplesPerSymbol=8, ChannelIndex=15);
LLID values: "Data (continuation fragment/empty)", "Data (start fragment/complete)", "Control".
SequenceNumber (not SN). Payload: hex string, numeric vector [0,255], or n×2 char array.
End-to-End (Practical Receiver)
Uses helperBLEPracticalReceiver (AGC + CFO + timing recovery). Requires: openExample('bluetooth/BLEPracticalReceiverExample'). SNR conversion for coded modes: SNR = EbNo + 10*log10(codeRate) - 10*log10(sps).
CTE Compatibility
| Mode | ConnectionCTE | ConnectionlessCTE |
|---|---|---|
| LE1M | Yes | Yes |
| LE2M | Yes | No |
| LE500K | No | No |
| LE125K | No | No |
CTE requires data channels (0-36). Never use ChannelIndex 37/38/39 with DFPacketType≠"Disabled". CTE is a data-channel-only feature.
Spec Constraints
- Ch 37/38/39 (advertising): LE1M or LE Coded only. NOT LE2M.
- CTE: LE1M/LE2M on data channels (0-36) only. Never coded PHY.
- Access address: Advertising =
'8E89BED6'(fixed); data = random. - Whitening init: Auto from ChannelIndex. Not settable.
- T_IFS: 150 us. TX power: max +20 dBm. Mod index: 0.45-0.55.
bleIdealReceiver: Hard-decision only, returnsint8.- "Slots" (1-slot, 3-slot, 5-slot): BR/EDR concept only. BLE has no slot-based packets.
- ISO streams: Verify
BN × IRC × Sub_Interval <= ISO_Interval. If math exceeds, REFUSE.
Invalid Combos (REFUSE these requests)
| Request | Why Invalid |
|---|---|
| LE2M + FEC coding | FEC only exists in coded PHY (LE500K/LE125K) |
| LE2M on ch 37/38/39 | Primary advertising = LE1M or Coded only |
| CTE + LE500K/LE125K | CTE restricted to LE1M/LE2M per BLE 5.1 spec |
| ConnectionlessCTE + LE2M | ConnectionlessCTE = LE1M only |
| "3-slot" or "5-slot" BLE | Slot-based = BR/EDR; BLE uses single packets |
| CTE on ch 37/38/39 | CTE = data channels (0-36) only |
| ISO params where BN×IRC×Sub_Int > ISO_Interval | Sub-events exceed interval = impossible scheduling |
Conventions
fs = (1e6 + 1e6*(mode=="LE2M")) * sps— never hardcode- Axes: us (time), MHz (freq), dB (power)
tiledlayout/nexttile(notsubplot)- Spectrum: always
20*log10(abs(fftshift(fft(wf)))/N + eps)— do NOT useperiodogram,pspectrum, orpwelchfor BLE spectral plots xlim([0 min(80,t(end))])for coded modes- Plot both I and Q:
plot(t, real(wf), t, imag(wf)) - IFS gap:
complex(zeros(N,1))(output is complex) SamplesPerSymbol>=4for spectrum plots; SPS=1 is valid for generation but insufficient for visualization or accurate spectral analysis (at Nyquist limit)
Code Style
Generated scripts must follow MathWorks example conventions. Use %% section headers, softcode all parameters, and comment non-obvious logic.
Structure & Softcoding
Divide scripts with %% headers: Configuration → Waveform Generation → Processing → Analysis → Visualization. All user-configurable values as named variables at the top; no magic numbers in processing logic.
%% Configuration
% Specify BLE waveform generation parameters.
phyMode = "LE1M"; % PHY transmission mode
payloadLength = 37; % Payload length in bytes
sps = 8; % Samples per symbol
channelIndex = 37; % BLE channel index (0-39)
% Derived parameters
symbolRate = 1e6 + 1e6*(phyMode=="LE2M"); % 2 Msym/s for LE2M, 1 Msym/s otherwise
fs = sps * symbolRate; % Sample rate in Hz
numBits = payloadLength * 8; % Payload length in bits
%% Waveform Generation
% Generate BLE waveform from random payload bits.
messageBits = randi([0 1], numBits, 1);
waveform = bleWaveformGenerator(messageBits, ...
Mode=phyMode, SamplesPerSymbol=sps, ChannelIndex=channelIndex);
Comments
- Inline (right-aligned): units, range, or brief purpose —
% Eb/No in dB - Block (above 2-5 lines): intent or why —
% IFS gap must be complex (bleWaveformGenerator output is complex) - Constraints: spec reference —
% LE2M uses 2 Msym/s (only mode with 2x symbol rate) - Do NOT comment self-evident lines, every line mechanically, or closing
endstatements
Naming
- camelCase:
messageBits,txWaveform,symbolRate,channelIndex - Descriptive loop counters:
countMode,pktIdx(noti,j) - Named constants:
bitsPerByte = 8,tIFS = 150e-6 - Multi-init:
[numErrors, perCount] = deal(0, 0)
Gotchas
| Mistake | Fix |
|---|---|
bleWaveformConfig(...) | Does not exist. Use bleWaveformGenerator(bits, NV...) directly |
bluetoothWaveformGenerator for BLE | BR/EDR only. Use bleWaveformGenerator |
comm.BLEReceiver | Does not exist. Use bleIdealReceiver |
symbolRate=1e6 for LE2M | LE2M = 2e6 |
'PHYMode' as param name | Use 'Mode' |
'LECODED' as mode | Use "LE500K" or "LE125K" |
| Config object as 1st arg | Must be binary col vector randi([0 1],N,1) |
Empty [] bits | Minimum 1 byte |
Real zeros() for IFS | Use complex(zeros(N,1)) |
| CTE + coded modes | CTE only on LE1M/LE2M |
ConnectionlessCTE + LE2M | LE1M only |
| LE2M on ch 37/38/39 | Spec violation. Use LE1M or Coded |
CTELength/CTEType as NV args | Not valid. Use DFPacketType |
bleAngleEstimate(wf, NV...) | Use bleAngleEstimate(iqSamples, bleAngleEstimateConfig) |
bleWaveformGenerator for RF-PHY | Use bluetoothTestWaveformConfig + bluetoothTestWaveform |
| AWGN without oversampling correction | Use convertSNR(EbNo,"ebno","snr",SamplesPerSymbol=sps); pass explicit power to awgn (never use "measured") |
bleIdealReceiver with impairments | Use helperBLEPracticalReceiver |
| Eb/No for coded modes without code rate | SNR = EbNo + 10*log10(codeRate) - 10*log10(sps) |
| SPS=1 without warning | SPS=1 is at Nyquist limit — warn user: no spectral analysis, marginal decode performance |
Timing ppm offset without resample | Apply clock drift via resample(wf, 1e6+ppm, 1e6) or fractional delay filter |
| Conformance Df1/Df2 without PRBS9 | Use comm.PNSequence (z^9+z^5+1) for TP/TRM/CA/BV-05-C; separate stable-bit (Df1) from alternating-bit (Df2) patterns |
periodogram/pwelch for BLE spectrum | Use manual fftshift(fft(wf)) — skill convention |
SN as property name | Use SequenceNumber on bleLLDataChannelPDUConfig |
Address with colons "A1:B2:..." | Use 12-char hex string without colons: "A1B2C3D4E5F6" |
PDUType="ADV_IND" | Use full string: "Advertising indication" |
| Binary vector as AdvertisingData | Use hex string: "0201060709..." (length-type-value) |
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