gusucode.com > wlan工具箱matlab源码程序 > wlan/wlan/wlanWaveformGenerator.m
function txWaveform = wlanWaveformGenerator(dataBits,cfgFormat,varargin)
% wlanWaveformGenerator WLAN waveform generation
% WAVEFORM = wlanWaveformGenerator(DATA,CFGFORMAT) generates a waveform
% for a given format configuration and information bits. The generated
% waveform contains a single packet with no idle time. For OFDM based
% formats, the data scrambler initial states is 93 and the packet is
% windowed for spectral controls with a windowing transition time of 1e-7
% seconds.
%
% WAVEFORM is a complex Ns-by-Nt matrix containing the generated
% waveform, where Ns is the number of time domain samples, and Nt is the
% number of transmit antennas.
%
% DATA is the information bits including any MAC padding to be coded
% across the number of packets to generate, i.e., representing multiple
% concatenated PSDUs. It can be a double or int8 typed binary vector.
% Alternatively, it can be a scalar cell array or a vector cell array
% with length equal to number of users. Each element of the cell array
% must be a double or int8 typed, binary vector. When DATA is a vector or
% scalar cell array, it applies to all users. When DATA is a vector cell
% array, each element applies to a single user. For each user, the bit
% vector applied is looped if the number of bits required across all
% packets of the generation exceeds the length of the vector provided.
% This allows a short pattern to be entered, e.g. [1;0;0;1]. This pattern
% will be repeated as the input to the PSDU coding across packets and
% users. The number of data bits taken from a data stream for the ith
% user when generating a packet is given by the ith element of the
% CFGFORMAT.PSDULength property times eight.
%
% CFGFORMAT is a format configuration object of type <a href="matlab:help('wlanVHTConfig')">wlanVHTConfig</a>,
% <a href="matlab:help('wlanHTConfig')">wlanHTConfig</a>, or <a href="matlab:help('wlanNonHTConfig')">wlanNonHTConfig</a>. The format of the generated waveform
% is determined by the type of CFGFORMAT. The properties of CFGFORMAT are
% used to parameterize the packets generated including the data rate and
% PSDU length.
%
% WAVEFORM = wlanWaveformGenerator(DATA,CFGFORMAT,Name,Value) specifies
% additional name-value pair arguments described below. When a name-value
% pair is not specified, its default value is used.
%
% 'NumPackets' The number of packets to generate. It must
% be a positive integer. The default value is
% 1.
%
% 'IdleTime' The length in seconds of an idle period
% after each generated packet. It must be 0 or
% greater than or equal to 2e-6 seconds. The
% default value is 0 seconds.
%
% 'ScramblerInitialization' Scrambler initial state(s), applied for OFDM
% based formats. It must be a double or
% int8-typed scalar or matrix containing
% integer values between 1 and 127 inclusive.
% If a scalar is provided all packets are
% initialized with the same state for all
% users. Specifying a matrix allows a
% different initial state to be used per user
% and per packet. Each column specifies the
% initial states for a single user. If a
% single column is provided, the same initial
% states will be used for all users. Each row
% represents the initial state of each packet
% to generate. Internally the rows are looped
% if the number of packets to generate exceeds
% the number of rows of the matrix provided.
% The default value is 93, which is the
% example state given in IEEE Std 802.11-2012
% Section L.1.5.2.
%
% 'WindowTransitionTime' The windowing transition length in seconds,
% applied to OFDM based formats. It must be a
% nonnegative scalar and no greater than
% 16e-6 seconds. Specifying it as 0 turns off
% windowing. The default value is 1e-7
% seconds.
% Examples:
%
% Example 1:
% % Generate a time domain signal txWaveform for an 802.11ac VHT
% % transmission with 10 packets and 20 microsecond idle period
% % between packets.
%
% numPkts = 10; % 10 packets in the waveform
%
% cfgVHT = wlanVHTConfig(); % Create format configuration
% % Change properties from defaults
% cfgVHT.NumTransmitAntennas = 2; % 2 transmit antennas
% cfgVHT.NumSpaceTimeStreams = 2; % 2 spatial streams
% cfgVHT.MCS = 1; % Modulation: QPSK Rate: 1/2
% cfgVHT.APEPLength = 1024; % A-MPDU length in bytes
%
% % Create bit vector containing concatenated PSDUs
% numBits = cfgVHT.PSDULength*8*numPkts;
% dataBits = randi([0 1],numBits,1);
%
% txWaveform = wlanWaveformGenerator(dataBits, cfgVHT, ...
% 'NumPackets', numPkts, 'IdleTime', 20e-6, ...
% 'WindowTransitionTime', 1e-7);
%
% Example 2:
% % Produce a waveform containing a single 802.11a packet without
% % any windowing.
%
% cfgNonHT = wlanNonHTConfig(); % Create format configuration
%
% psdu = randi([0 1], cfgNonHT.PSDULength*8, 1); % Create a PSDU
%
% txWaveform = wlanWaveformGenerator(psdu, cfgNonHT, ...
% 'WindowTransitionTime', 0); % Disable windowing
%
% See also wlanVHTConfig, wlanHTConfig, wlanNonHTConfig, wlanS1GConfig.
% Copyright 2015-2016 The MathWorks, Inc.
%#codegen
% Check number of input arguments
coder.internal.errorIf((nargin ~= 3) && mod(nargin, 2) == 1, ...
'wlan:wlanWaveformGenerator:InvalidNumInputs');
% Validate the format configuration object is a valid type
validateattributes(cfgFormat, ...
{'wlanVHTConfig','wlanHTConfig','wlanNonHTConfig','wlanS1GConfig'}, ...
{'scalar'}, mfilename, 'format configuration object');
s = validateConfig(cfgFormat);
inDSSSMode = isa(cfgFormat,'wlanNonHTConfig') && ...
strcmpi(cfgFormat.Modulation,'DSSS');
% Set maximum limits for windowing transition time based on bandwidth and
% format for the validity check performed later.
maxWinTransitTime = 6.4e-6; % default
maxWinTransitTimeStr = '6.4e-06'; % string for codegen
switch class(cfgFormat)
case 'wlanNonHTConfig'
if strcmpi(cfgFormat.Modulation, 'OFDM')
switch cfgFormat.ChannelBandwidth
case 'CBW5'
maxWinTransitTime = 6.4e-6; % seconds
maxWinTransitTimeStr = '6.4e-06';
case 'CBW10'
maxWinTransitTime = 3.2e-6; % seconds
maxWinTransitTimeStr = '3.2e-06';
otherwise % 'CBW20'
maxWinTransitTime = 1.6e-6; % seconds
maxWinTransitTimeStr = '1.6e-06';
end
end
case 'wlanS1GConfig'
maxWinTransitTime = 16e-6; % seconds
maxWinTransitTimeStr = '16e-06';
otherwise % HT/VHT
maxWinTransitTime = 1.6e-6; % seconds
maxWinTransitTimeStr = '1.6e-06'; % default
end
if nargin == 3 % wlanGeneratorConfig
cfgWaveGen = varargin{1};
% Validate the waveform generator config object is the correct type
validateattributes(cfgWaveGen, {'wlanGeneratorConfig'}, {'scalar'}, ...
mfilename, 'waveform generator configuration object');
numPackets = cfgWaveGen.NumPackets;
idleTime = cfgWaveGen.IdleTime;
scramblerInit = cfgWaveGen.ScramblerInitialization;
winTransitTime = cfgWaveGen.WindowTransitionTime;
windowing = (~inDSSSMode) && (cfgWaveGen.Windowing) && (winTransitTime > 0);
coder.internal.errorIf(windowing && (winTransitTime > maxWinTransitTime), ...
'wlan:wlanWaveformGenerator:ExceededMaxTransitionTime', ...
maxWinTransitTimeStr);
else % P-V pairs
% Define default P-V pair values
numPackets = 1;
idleTime = 0;
scramblerInit = 93;
winTransitTime = 1e-7;
% Validate each P-V pair
for i = 3:2:nargin
prop = varargin{i-2};
val = varargin{i-1};
coder.internal.errorIf(~ischar(prop) || ...
~any(strcmp(prop, {'NumPackets', 'IdleTime', ...
'ScramblerInitialization', 'WindowTransitionTime'})), ...
'wlan:wlanWaveformGenerator:InvalidProperty');
switch prop
case 'NumPackets'
validateattributes(val,{'numeric'},{'scalar','integer','>=',0}, ...
mfilename,'''NumPackets'' value');
numPackets = val;
case 'IdleTime'
validateattributes(val,{'numeric'}, ...
{'scalar','real','>=',0},mfilename,'''IdleTime'' value');
coder.internal.errorIf((val > 0) && (val < 2e-6), ...
'wlan:wlanWaveformGenerator:InvalidIdleTimeValue');
idleTime = val;
case 'ScramblerInitialization'
if ~inDSSSMode
validateattributes(val,{'double','int8'}, ...
{'real','integer','2d','nonempty','>=',1,'<=',127}, ...
mfilename,'''ScramblerInitialization'' value');
end
scramblerInit = val;
otherwise % 'WindowTransitionTime'
if ~inDSSSMode
validateattributes(val, {'numeric'}, ...
{'real','scalar','>=',0,'<=',maxWinTransitTime}, ...
mfilename,'''WindowTransitionTime'' value');
end
winTransitTime = val;
end
end
windowing = (~inDSSSMode) && (winTransitTime > 0);
end
if isa(cfgFormat,'wlanVHTConfig') || isa(cfgFormat,'wlanS1GConfig')
numUsers = cfgFormat.NumUsers;
else
numUsers = 1;
end
% Cross validation
coder.internal.errorIf( ...
all(size(scramblerInit, 2) ~= [1 numUsers]), ...
'wlan:wlanWaveformGenerator:ScramInitNotMatchNumUsers');
% Validate that data bits are present if PSDULength is nonzero
if iscell(dataBits) % SU and MU
% Data must be a scalar cell or a vector cell of length Nu
coder.internal.errorIf(~isvector(dataBits) || ...
all(length(dataBits) ~= [1 numUsers]), ...
'wlan:wlanWaveformGenerator:InvalidDataCell');
for u = 1:length(dataBits)
if ~isempty(dataBits{u}) && any(cfgFormat.PSDULength > 0) % Data packet
validateattributes(dataBits{u}, {'double','int8'}, ...
{'real','integer','vector','binary'}, ...
mfilename, 'each element in cell data input');
else
% Empty data check if not NDP
coder.internal.errorIf( ...
any(cfgFormat.PSDULength > 0) && isempty(dataBits{u}), ...
'wlan:wlanWaveformGenerator:NoData');
end
end
if (numUsers > 1) && isscalar(dataBits)
% Columnize and expand to a [1 Nu] cell
dataCell = repmat({int8(dataBits{1}(:))}, 1, numUsers);
else % Columnize each element
dataCell = repmat({int8(1)}, 1, numUsers);
for u = 1:numUsers
dataCell{u} = int8(dataBits{u}(:));
end
end
else % SU and MU: Data must be a vector
if ~isempty(dataBits) && any(cfgFormat.PSDULength > 0) % Data packet
validateattributes(dataBits, {'double','int8'}, ...
{'real','integer','vector','binary'}, ...
mfilename, 'Data input');
% Columnize and expand to a [1 Nu] cell
dataCell = repmat({int8(dataBits(:))}, 1, numUsers);
else % NDP
% Empty data check if not NDP
coder.internal.errorIf(any(cfgFormat.PSDULength > 0) && isempty(dataBits), ...
'wlan:wlanWaveformGenerator:NoData');
dataCell = {int8(dataBits(:))};
end
end
% Number of bits in a PSDU for a single packet (convert bytes to bits)
numPSDUBits = cfgFormat.PSDULength*8;
% Repeat to provide initial state(s) for all users and packets
scramInit = repmat(scramblerInit, 1, ...
numUsers/size(scramblerInit, 2)); % For all users
pktScramInit = scramInit(mod((0:numPackets-1).', size(scramInit, 1))+1, :);
% Get the sampling rate of the waveform
if inDSSSMode % DSSS format
sr = 11e6;
numTxAnt = 1;
giType = ''; % for codegen
FFTLen = 0; % for codegen
info = wlan.internal.dsssInfo(cfgFormat);
numPktSamples = info.NumPPDUSamples;
lstf = []; % for codegen
lltf = []; % for codegen
lsig = []; % for codegen
else % OFDM format
chanBW = cfgFormat.ChannelBandwidth;
sr = wlan.internal.cbwStr2Num(chanBW)*1e6;
switch class(cfgFormat)
case 'wlanNonHTConfig'
giType = 'Long'; % Always
FFTLen = 64;
case 'wlanS1GConfig'
giType = cfgFormat.GuardInterval;
FFTLen = (sr/2e6)*64;
otherwise % For VHT/HT formats
giType = cfgFormat.GuardInterval;
FFTLen = (sr/20e6)*64;
end
if (strcmp(chanBW, 'CBW10') || strcmp(chanBW, 'CBW5'))
numTxAnt = 1; % override and set to 1 only, for 802.11j/p
else
numTxAnt = cfgFormat.NumTransmitAntennas;
end
numPktSamples = real(s.NumPPDUSamples); % real for codegen
% Generate the legacy preamble fields for applicable formats
if ~isa(cfgFormat, 'wlanS1GConfig')
lstf = wlanLSTF(cfgFormat);
lltf = wlanLLTF(cfgFormat);
lsig = wlanLSIG(cfgFormat);
end
end
if isa(cfgFormat, 'wlanVHTConfig') % VHT format
% VHT Format
vhtsiga = wlanVHTSIGA(cfgFormat);
vhtstf = wlanVHTSTF(cfgFormat);
vhtltf = wlanVHTLTF(cfgFormat);
vhtsigb = wlanVHTSIGB(cfgFormat);
preamble = [lstf; lltf; lsig; vhtsiga; vhtstf; vhtltf; vhtsigb];
elseif isa(cfgFormat, 'wlanHTConfig') % HT-MF format
htSig = wlanHTSIG(cfgFormat);
htstf = wlanHTSTF(cfgFormat);
htltf = wlanHTLTF(cfgFormat);
preamble = [lstf; lltf; lsig; htSig; htstf; htltf];
elseif isa(cfgFormat, 'wlanNonHTConfig')
if strcmp(cfgFormat.Modulation, 'OFDM')
preamble = [lstf; lltf; lsig];
else % DSSS
preamble = [wlan.internal.wlanDSSSPreamble(cfgFormat); ...
wlan.internal.wlanDSSSHeader(cfgFormat)];
end
elseif isa(cfgFormat, 'wlanS1GConfig')
if isS1G1MConfig(cfgFormat) || isS1GShortConfig(cfgFormat)
stf = wlan.internal.s1gSTF(cfgFormat);
[ltf1, ltf2n] = wlan.internal.s1gLTF(cfgFormat);
sig = wlan.internal.s1gSIG(cfgFormat);
preamble = [stf; ltf1; sig; ltf2n];
else % Preamble == 'Long'
stf = wlan.internal.s1gSTF(cfgFormat);
ltf1 = wlan.internal.s1gLTF1(cfgFormat);
siga = wlan.internal.s1gSIGA(cfgFormat);
dstf = wlan.internal.s1gDSTF(cfgFormat);
dltf = wlan.internal.s1gDLTF(cfgFormat);
sigb = wlan.internal.s1gSIGB(cfgFormat);
preamble = [stf; ltf1; siga; dstf; dltf; sigb];
end
end
if windowing
% Calculate parameters for windowing
% IdleSample offset due to windowing
wlength = 2*ceil(winTransitTime*sr/2);
bLen = wlength/2; % Number of samples overlap at end of packet
aLen = bLen-1; % Number of samples overlap at start of packet
windowedPktLength = numPktSamples+wlength-1;
else
% Define unused windowing variables for codegen
wlength = 0;
windowedPktLength = numPktSamples+wlength-1;
aLen = 0;
bLen = 0;
end
% Define a matrix of total simulation length
numIdleSamples = round(sr*idleTime);
pktWithIdleLength = numPktSamples+numIdleSamples;
txWaveform = complex(zeros(numPackets*pktWithIdleLength,numTxAnt));
for i = 1:numPackets
% Extract PSDU for the current packet
psdu = getPSDUForCurrentPacket(dataCell, numPSDUBits, i);
% Generate the PSDU with the correct scrambler initial state
if isa(cfgFormat, 'wlanVHTConfig')
if any(cfgFormat.APEPLength > 0)
data = wlanVHTData(psdu, cfgFormat, pktScramInit(i, :));
else % NDP
data = complex(zeros(0, cfgFormat.NumTransmitAntennas));
end
elseif isa(cfgFormat, 'wlanHTConfig') % HT-MF format
if cfgFormat.PSDULength > 0
data = wlanHTData(psdu{1}, cfgFormat, pktScramInit(i, :));
else % NDP or sounding packet
data = complex(zeros(0, cfgFormat.NumTransmitAntennas));
end
elseif isa(cfgFormat, 'wlanNonHTConfig') % NonHT format
if strcmp(cfgFormat.Modulation, 'OFDM')
data = wlanNonHTData(psdu{1}, cfgFormat, pktScramInit(i, :));
else % DSSS
data = wlan.internal.wlanDSSSData(psdu{1}, cfgFormat);
end
elseif isa(cfgFormat, 'wlanS1GConfig') % S1G format
data = wlan.internal.s1gData(psdu, cfgFormat, pktScramInit(i, :));
end
% Construct packet from preamble and data
packet = [preamble; data];
if windowing
if isa(cfgFormat, 'wlanS1GConfig') && strcmp(cfgFormat.GuardInterval, 'Short')
% For S1G the first data symbol is always Long GI
numSamplesSymbol = 40e-6*sr; %40 us from Table 24.4 IEEE P802.11ah/D5.0
numSamplesBeforeShortGI = size(preamble,1)+numSamplesSymbol;
else
% For other formats short GI begins after the preamble
numSamplesBeforeShortGI = size(preamble,1);
end
% Window each packet
windowedPacket = wlan.internal.wlanWindowing(packet, FFTLen, ...
wlength, giType, numSamplesBeforeShortGI);
% Overlap-add the windowed packets
if numPackets==1 && numIdleSamples==0 % Only one packet which wraps
txWaveform = windowedPacket(aLen+(1:numPktSamples), :);
% Overlap start of packet with end
txWaveform(1:bLen, :) = txWaveform(1:bLen, :)+ ...
windowedPacket(end-bLen+1:end, :);
% Overlap end of packet with start
txWaveform(end-aLen+1:end, :) = txWaveform(end-aLen+1:end, :)+ ...
windowedPacket(1:aLen, :);
else
if i==1 % First packet (which wraps)
% First packet wraps to end of waveform
txWaveform(1:(numPktSamples+bLen), :) = ...
windowedPacket(1+aLen:end, :);
txWaveform(end-aLen+1:end, :) = windowedPacket(1:aLen, :);
elseif i==numPackets && numIdleSamples==0 % Last packet which wraps
% Last packet wraps to start of waveform
startIdx = (i-1)*pktWithIdleLength-aLen+1;
txWaveform(startIdx:end, :) = txWaveform(startIdx:end, :)+ ...
windowedPacket(1:end-bLen, :);
txWaveform(1:bLen,:) = txWaveform(1:bLen, :)+ ...
windowedPacket(end-bLen+1:end, :);
else % Packet does not wrap
% Normal windowing overlap between packets
idx = (i-1)*pktWithIdleLength-aLen+(1:windowedPktLength);
txWaveform(idx, :) = txWaveform(idx, :)+windowedPacket;
end
end
else
% Construct entire waveform
txWaveform((i-1)*pktWithIdleLength+(1:numPktSamples), :) = packet;
end
end
end
function psdu = getPSDUForCurrentPacket(dataCell, numPSDUBitsPerPacket, ...
packetIdx)
numUsers = length(dataCell); % == length(numPSDUBits)
psdu = repmat({int8(1)}, 1, numUsers); % Cannot use cell(1, numUsers) for codegen
for u = 1:numUsers
idx = mod((packetIdx-1)*numPSDUBitsPerPacket(u)+...
(0:numPSDUBitsPerPacket(u)-1).', length(dataCell{u})) + 1;
psdu{u} = dataCell{u}(idx);
end
end
% [EOF]