matlab-generate-ble-waveform

name: matlab-generate-ble-waveform description: > 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+. license: MathWorks BSD-3-Clause compatibility: ">=R2022a" metadata: author: MathWorks version: "1.0"

BLE Waveform Generation

Routing

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

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)

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

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)

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

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