Документация

% Check if the 'Communications Toolbox Library for the Bluetooth Protocol'
% support package is installed or not.
commSupportPackageCheck('BLUETOOTH');

% Select PHY transmission mode {'LE1M','LE2M'} as per Bluetooth RF-PHY Test
% Specifications
phyMode = "LE1M";
% Select frequency of operation for IUT based on the generic access profile
% (GAP) role(s) as shown in the table below.
%  --------------------------------------------------------------------------------
% | Operating |  Peripheral & Central Devices    |  Broadcaster & Observer Devices |
% | Frequency |                                  |                                 |
% | (MHz)     |----------------------------------|---------------------------------|
% |           | Output Power | In-band Emissions | Output Power | In-band Emissions|
% |           |     Test     |        Test       |     Test     |        Test      |    
% |-----------|--------------|-------------------|--------------|------------------|
% | Lowest    |    2402      |       2406        |     2402     |       2402       |
% | Middle    |    2440      |       2440        |     2426     |       2440       |
% | Highest   |    2480      |       2476        |     2480     |       2480       |
%  --------------------------------------------------------------------------------
ФК = 2440e6; % Frequency of operation in Hz
payloadLength = 37; % Payload length in bytes, must be in the range [37,255]
SPS = 32; % Number of samples per symbol, minimum of 32 sps as per the test specifications
outputPower = 20; % Output power in dBm, must be in the range [-20,20]
numDominantFreq = 6; % Select number of dominant frequencies for in-band emissions test, must
% be in the range [1,78] and [1,74] for LE1M and LE2M modes, respectively.

% The number of dominant frequencies represents the number of test
% frequencies near the operating frequency at which the in-band emissions
% test is to be performed. The number chosen in this example leads to a
% short simulation. For performing complete in-band emissions test, change
% the |numDominantFreq| parameter to maximum number of dominant frequencies
% as specified in the Section 4.4.2 of the Bluetooth RF-PHY Test
% Specifications.

payloadType = 0; % Payload type for PRBS9 sequence
waveform =  helperBLETestWaveform(payloadType,payloadLength,sps,phyMode);

% Calculate sampling rate in Hz based on PHY transmission mode
Rsym = 1e6;
if strcmp(phyMode,'LE2M')
    Rsym = 2e6;
end
Fs = Rsym*sps;

% Apply frequency upconversion to obtain a passband signal for the
% specified frequency of operation.
maxFreq = 2485e6; % in Hz
interpFactor = ceil(2*maxFreq/Fs); % Interpolation factor for upconversion to
                                   % cover BLE RF frequency band (2400e6 to 2485e6)

% Change the stopband frequency in Hz based on the PHY transmission mode
stopbandFreq = 2e6;
if strcmp(phyMode,'LE2M')
    stopbandFreq = 4e6;
end

% Create a digital upconverter System object
upConv = dsp.DigitalUpConverter(...
              'InterpolationFactor', interpFactor,...
              'SampleRate', Fs,...
              'Bandwidth', 2e6,...
              'StopbandAttenuation', 44,...
              'PassbandRipple',0.5,...
              'CenterFrequency',Fc,...
              'StopbandFrequencySource','Property',...
              'StopbandFrequency', stopbandFreq);

% Upconvert the baseband waveform to passband
dBdBmConvFactor = 30;
scalingFactor = 10^((outputPower-dBdBmConvFactor)/20);
upConvWaveform = scalingFactor*upConv(waveform);

rbwOutputPower = 3e6; % Resolution bandwidth, in Hz
% Frequency span must be zero so that the power measurement is performed in
% the time domain. Span 0 can be replicated by taking power values from the
% spectrogram at frequency of operation (Fc). Frequency limits are
% considered starting from frequency of operation (Fc) up to maximum
% frequency in the frequency band.
[P,F,T] = pspectrum(upConvWaveform,interpFactor*Fs,'spectrogram',...
                               'TimeResolution',1/rbwOutputPower,...
                               'FrequencyLimits',[Fc,maxFreq]);
powerAtFc = P(1,:); % Extract power values at Fc (F(1) = Fc)
% Calculate average power, AVGPOWER over at least 20% to 80% of the
% duration of the burst as specified in Section 4.4.1 of the Bluetooth
% RF-PHY Test Specifications.
powerAvgStartIdx = floor(0.2*length(powerAtFc));
powerAvgStopIdx = floor(0.8*length(powerAtFc));
avgPower = 10*log10(mean(powerAtFc(powerAvgStartIdx:powerAvgStopIdx)))+dBdBmConvFactor;
% Calculate peak power, PEAKPOWER
peakPower = 10*log10(max(powerAtFc))+dBdBmConvFactor;

% Plot power vs time
powerAtFcdBm = 10*log10(powerAtFc) + dBdBmConvFactor;
figure,plot(T,powerAtFcdBm)
grid on;
xlabel('Time(sec)');
ylabel('Power(dBm)');
title('Measured Output Power');

% Pass verdict - All measured values shall fulfill the following conditions:
%
% * Peak power <= (Average power + 3 dB)
% * -20dBm <= Average power <= 20dBm
%
fprintf('Measured average power and peak power are %f dBm and %f dBm, respectively.\n',avgPower,peakPower);

if (-20 <= avgPower <= 20) && (peakPower <= (avgPower+3))
    fprintf('Output power test passed.\n');
else
    fprintf('Output power test failed.\n');
end

% The function, <matlab:edit('helperBLEInbandEmissionsParams.m')
% helperBLEInbandEmissionsParams.m>, is configured to generate dominant
% test frequency parameters.
[testFreq,idx1,idx2] = helperBLEInbandEmissionsParams(Fc,numDominantFreq,phyMode);

% For each test frequency measure the power levels at the following 10
% frequencies.
numOffsets = 10;
freqOffset = -450e3+(0:numOffsets-1)*100e3;
adjChannelFreqOffsets = (freqOffset+testFreq-Fc).';

% Create and configure a spectrum analyzer for the waveform sampling rate
% and a resolution bandwidth of 100 kHz as specified in Section 4.4.2 of
% the Bluetooth RF-PHY Test Specifications.
rbw = 100e3; % Resolution bandwidth, in Hz
spectrumScope = dsp.SpectrumAnalyzer( ...
                'SampleRate',            Fs*interpFactor,...
                'SpectralAverages',      10, ...
                'YLimits',               [-120 30], ...
                'Title',                 'Power Spectrum of In-band Emissions',...
                'YLabel',                'Power (dBW)',...
                'SpectrumUnits',         'dBW',...
                'ShowLegend',            true,...
                'FrequencySpan',         'Start and stop frequencies',...
                'StartFrequency',         2400e6,...
                'StopFrequency',          maxFreq,...
                'RBWSource',             'Property',...
                'RBW',                    rbw,...
                'PlotMaxHoldTrace',       true,...
                'PlotAsTwoSidedSpectrum', false);

spectrumScope.ChannelMeasurements.Enable = true;
spectrumScope.ChannelMeasurements.Algorithm = 'ACPR';
spectrumScope.ChannelMeasurements.CenterFrequency = Fc;
spectrumScope.ChannelMeasurements.Span = 2e6; % Main channel bandwidth
spectrumScope.ChannelMeasurements.AdjacentBW = 1e5; % Adjacent channel bandwidth
spectrumScope.ChannelMeasurements.NumOffsets = numOffsets;

% Compute adjacent channel power ratio (ACPR) for the transmitted waveform
acpr = zeros(numOffsets,numDominantFreq);
for i = 1:numDominantFreq
    % Assign the 10 frequency offsets at each test frequency to ACPR Offsets
    spectrumScope.ChannelMeasurements.ACPROffsets = adjChannelFreqOffsets(:,i);

    % Estimate the power spectrum of the transmitted waveform using the spectrum analyzer
    spectrumScope(upConvWaveform);

    % Compute ACPR
    data = getMeasurementsData(spectrumScope); % Get the measurements data
    mainChannelPower = data.ChannelMeasurements.ChannelPower; % Main channel power at Fc
    acpr(:,i) = data.ChannelMeasurements.ACPRUpper; % Extract the ACPR values
end

% Power levels at 10 frequency offsets at each test frequency are
% calculated by adding main channel power to ACPR.
adjChannelPower = acpr(:,1:numDominantFreq) + mainChannelPower;

% Compute the power at each test frequency by adding all the powers
% measured at 10 frequency offsets.
adjPowerAtTestFreq = 10*log10(sum(10.^(adjChannelPower(:,1:numDominantFreq)/10))) + dBdBmConvFactor;

% Plot the adjacent channel powers
tick = 1:numel(adjPowerAtTestFreq);
ticklabel = testFreq/1e9;
figure;
bar(adjPowerAtTestFreq, 'BaseValue', -120, 'FaceColor', 'yellow');
set(gca, 'XTick', tick, 'XTickLabel', ticklabel, 'YLim', [-120 -20]);
for i = tick
    text(i, adjPowerAtTestFreq(i), sprintf('%0.2f',adjPowerAtTestFreq(i)), ...
        'HorizontalAlignment', 'Center', 'VerticalAlignment', 'Top');
end
title('In-Band Emission Test Measurement');
xlabel('Frequency (GHz)');
ylabel('Power (dBm)');

% Pass verdict- All measured values shall fulfill the following conditions:
% For LE1M PHY transmission mode
%
% * powerAtTestFreq <= -20 dBm for testFreq = Fc ± 2 MHz
% * powerAtTestFreq <= -30 dBm for testFreq = Fc ± [3+n] MHz; where
%   n=0,1,2,...
%
% For LE2M PHY transmission mode
%
% * powerAtTestFreq <= -20 dBm for testFreq = Fc ± 4 MHz AND testFreq = Fc
% ± 5 MHz
% * powerAtTestFreq <= -30 dBm for testFreq = Fc ± [6+n] MHz; where
%   n=0,1,2,...
%
for i = 1:numDominantFreq
    fprintf('Measured power at test frequency (Fc%+de6) is %.3f dBm.\n',(Fc-testFreq(i))*1e-6,adjPowerAtTestFreq(i));
end

if (all(adjPowerAtTestFreq(idx1) <= -20)||isempty(idx1)) && (all(adjPowerAtTestFreq(idx2) <= -30)||isempty(idx2))
    fprintf('In-band emissions test passed.\n');
else
    fprintf('In-band emissions test failed.\n');
end