BLE Waveform Generation

SkillDev tools

Generate 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.

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

IntentCuesPattern
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 bluetoothLENode for link-layer/network modeling
  • Path loss modeling → use bluetoothPathLoss for propagation/channel modeling

PHY Modes

ModesymbolRateData RateCodingDuration (37 B)
"LE1M"1e61 MbpsNone~336 us
"LE2M"2e62 MbpsNone~172 us
"LE500K"1e6500 kbpsFEC S=2~974 us
"LE125K"1e6125 kbpsFEC S=8~2768 us

References

For detailed guidance beyond what's in this file, see:

Parameters (bleWaveformGenerator)

ParamDefaultRange
Mode"LE1M"LE1M, LE2M, LE500K, LE125K
ChannelIndex370-39
SamplesPerSymbol8>=1 (use >=4 for plots)
WhitenStatus"On"On, Off
DFPacketType"Disabled"Disabled, ConnectionCTE, ConnectionlessCTE
AccessAddressadv default32-bit binary col vector
ModulationIndex0.5[0.45, 0.55]
PulseLength1[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

ModeConnectionCTEConnectionlessCTE
LE1MYesYes
LE2MYesNo
LE500KNoNo
LE125KNoNo

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, returns int8.
  • "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)

RequestWhy Invalid
LE2M + FEC codingFEC only exists in coded PHY (LE500K/LE125K)
LE2M on ch 37/38/39Primary advertising = LE1M or Coded only
CTE + LE500K/LE125KCTE restricted to LE1M/LE2M per BLE 5.1 spec
ConnectionlessCTE + LE2MConnectionlessCTE = LE1M only
"3-slot" or "5-slot" BLESlot-based = BR/EDR; BLE uses single packets
CTE on ch 37/38/39CTE = data channels (0-36) only
ISO params where BN×IRC×Sub_Int > ISO_IntervalSub-events exceed interval = impossible scheduling

Conventions

  • fs = (1e6 + 1e6*(mode=="LE2M")) * sps — never hardcode
  • Axes: us (time), MHz (freq), dB (power)
  • tiledlayout/nexttile (not subplot)
  • Spectrum: always 20*log10(abs(fftshift(fft(wf)))/N + eps) — do NOT use periodogram, pspectrum, or pwelch for 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>=4 for 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 end statements

Naming

  • camelCase: messageBits, txWaveform, symbolRate, channelIndex
  • Descriptive loop counters: countMode, pktIdx (not i, j)
  • Named constants: bitsPerByte = 8, tIFS = 150e-6
  • Multi-init: [numErrors, perCount] = deal(0, 0)

Gotchas

MistakeFix
bleWaveformConfig(...)Does not exist. Use bleWaveformGenerator(bits, NV...) directly
bluetoothWaveformGenerator for BLEBR/EDR only. Use bleWaveformGenerator
comm.BLEReceiverDoes not exist. Use bleIdealReceiver
symbolRate=1e6 for LE2MLE2M = 2e6
'PHYMode' as param nameUse 'Mode'
'LECODED' as modeUse "LE500K" or "LE125K"
Config object as 1st argMust be binary col vector randi([0 1],N,1)
Empty [] bitsMinimum 1 byte
Real zeros() for IFSUse complex(zeros(N,1))
CTE + coded modesCTE only on LE1M/LE2M
ConnectionlessCTE + LE2MLE1M only
LE2M on ch 37/38/39Spec violation. Use LE1M or Coded
CTELength/CTEType as NV argsNot valid. Use DFPacketType
bleAngleEstimate(wf, NV...)Use bleAngleEstimate(iqSamples, bleAngleEstimateConfig)
bleWaveformGenerator for RF-PHYUse bluetoothTestWaveformConfig + bluetoothTestWaveform
AWGN without oversampling correctionUse convertSNR(EbNo,"ebno","snr",SamplesPerSymbol=sps); pass explicit power to awgn (never use "measured")
bleIdealReceiver with impairmentsUse helperBLEPracticalReceiver
Eb/No for coded modes without code rateSNR = EbNo + 10*log10(codeRate) - 10*log10(sps)
SPS=1 without warningSPS=1 is at Nyquist limit — warn user: no spectral analysis, marginal decode performance
Timing ppm offset without resampleApply clock drift via resample(wf, 1e6+ppm, 1e6) or fractional delay filter
Conformance Df1/Df2 without PRBS9Use 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 spectrumUse manual fftshift(fft(wf)) — skill convention
SN as property nameUse 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 AdvertisingDataUse hex string: "0201060709..." (length-type-value)

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