gusucode.com > wlan工具箱matlab源码程序 > wlan/wlan/+wlan/+internal/vhtGetSTSPerUser.m
function y = vhtGetSTSPerUser(paddedData,scramInitBits,mcsTable,chanBW,numOFDMSym,userIdx,numSTS,varargin)
%vhtGetSTSPerUser Encode, parse and map bits to create space-time streams
%
% Note: This is an internal undocumented function and its API and/or
% functionality may change in subsequent releases.
%
% Y = vhtGetSTSPerUser(DATA,SCAM,MCSTABLE,CHANBW,NUMSYM,USERIDX,NUMSTS)
% performs scrambling, encoding, stream parsing, segment parsing,
% interleaving, constellation mapping and segment deparsing to form
% complex 'BCC' encoded symbols representing the space-time stream for a
% user.
%
% Y = vhtGetSTSPerUser(...,CHANNELCODING,NUMSYMMAXINIT,MSTBC) performs
% scrambling, encoding, stream parsing, segment parsing, interleaving,
% constellation mapping and segment deparsing to form complex 'BCC' or
% 'LDPC' encoded symbols representing the space-time stream for a user.
%
% DATA is the padded PSDU with service bits.
%
% SCRAM is the scrambler initialization bits.
%
% MCSTABLE is a structure array containing the rate information for all
% users.
%
% CHANBW is a string specifying the channel bandwidth.
%
% NUMSYM is the number of OFDM symbols.
%
% USERIDX is the user index of interest and is used to index into
% MCSTABLE.
%
% NUMSTS is the number of space-time streams for the user.
%
% CHANNELCODING specifies the coding type as one of 'BCC' or 'LDPC'. The
% default is set to 'BCC' encoding.
%
% NUMSYMMAXINIT is the number of OFDM symbols resulted due to LDPC
% encoding as specified in IEEE Std 802.11ac(TM)-2013, Section
% 22.3.10.5.5, Eq 22-65. The NUMSYMMAXINIT is the initial maximum number
% of symbols without adding any extra symbols due to LDPC. The
% NUMSYMMAXINIT input is only required for LDPC.
%
% MSTBC specifies the space-time block coding in the data field
% transmission. The MSTBC of one mean no STBC. The STBC value of two
% considers STBC in the calculation of LDPC encoding parameters. The
% MSTBC input is only required for LDPC encoding.
% Copyright 2016 The MathWorks, Inc.
%#codegen
narginchk(7,10);
if nargin == 7
channelCoding = 'BCC';
else
channelCoding = varargin{1};
numSymMaxInit = varargin{2};
mSTBC = varargin{3};
end
chanBWMHz = str2double(chanBW(4:end));
numES = mcsTable.NES(userIdx);
numSS = mcsTable.Nss(userIdx);
rate = mcsTable.Rate(userIdx);
numBPSCS = mcsTable.NBPSCS(userIdx);
numCBPS = mcsTable.NCBPS(userIdx);
numDBPS = mcsTable.NDBPS(userIdx);
numSeg = 1 + any(strcmp(chanBW, {'CBW16', 'CBW160'}));
numCBPSSI = numCBPS/numSS/numSeg;
scrambData = wlan.internal.wlanScramble(paddedData, scramInitBits);
if strcmp(channelCoding, 'BCC')
% BCC Encoding
% Reshape scrambled data as per IEEE Std 802.11ac-2013, Eq. 22-60
% for multiple encoders
numTailBits = 6;
encodedStreams = reshape(scrambData, numES, []).';
encodedData = zeros(round((size(encodedStreams,1)+numTailBits)/rate), numES, 'int8');
for i = 1:numES
% BCC encoding, Section 22.3.10.5.3, IEEE Std 802.11ac-2013
encodedData(:, i) = wlan.internal.wlanBCCEncode([encodedStreams(:, i); ...
zeros(numTailBits,1)], rate);
end
else
% LDPC Encoding as specified in IEEE Std 802.11-2012, 802.11ac-2013,
% Section 20.3.11.17.5 and Section 22.3.10.5.4 repectively.
numPLD = numSymMaxInit*numDBPS; % Number of payload bits, Eq 22-61
cfg = wlan.internal.getLDPCparameters(numDBPS, rate, mSTBC, numPLD, numOFDMSym);
encodedData = wlan.internal.wlanLDPCEncode(scrambData, cfg);
end
% Repetition coding
% Repeat encoded data for S1G MCS 10
if (rate==1/2)&&(numDBPS==6) % rate and Ndbps for S1G MCS10
repeatedData = wlan.internal.repetitionForMCS10(encodedData);
else
repeatedData = encodedData;
end
% Parse encoded data into streams
% Section 22.3.10.6, IEEE Std 802.11ac-2013
streamParsedData = wlan.internal.wlanStreamParser(repeatedData, numSS, numBPSCS);
% Segment parsing for 16, 160, 80+80 MHz
% Section 22.3.10.7, IEEE Std 802.11ac-2013
parsedData = wlan.internal.wlanSegmentParser(streamParsedData, chanBW, ...
numBPSCS, numCBPS, numES, 'Tx');
% Interleaving, constellation mapping and segment deparsing
mappedData = complex(zeros(numCBPSSI/numBPSCS, numSS, numSeg));
% [Nsd, Nsym, Nss]
ssPerUser = complex(zeros(numCBPSSI/numBPSCS*numSeg, numOFDMSym, numSS));
if strcmp(channelCoding, 'BCC')
interleavedData = zeros(numCBPSSI, numSS, numSeg);
for i = 1:numOFDMSym
for segIdx = 1:numSeg % Frequency segmentation, if needed
% Interleaving, Section 22.3.10.8, IEEE Std 802.11ac-2013,
% Section 24.3.9.8, IEEE Std P802.11ah/D5.0
interleavedData(:, :, segIdx) = wlan.internal.wlanBCCInterleave( ...
parsedData((i-1)*numCBPSSI + (1:numCBPSSI).', :, segIdx), ...
'VHT', numCBPSSI, numBPSCS, chanBWMHz, numSS);
% Constellation mapping, Section 22.3.10.9, IEEE Std 802.11ac-2013
mappedData(:, :, segIdx) = wlan.internal.wlanConstellationMapper( ...
interleavedData(:, :, segIdx), numBPSCS);
end
% Frequency deparsing, Section 22.3.10.9.3, IEEE Std 802.11ac-2013
ssPerUser(:,i,:) = reshape(wlan.internal.wlanSegmentDeparser( ...
mappedData, chanBW, 'Tx'), [], 1, numSS);
end
else
% LDPC tone mapping index as specified in IEEE 802.11ac-2013, Section
% 22.3.10.19.2.
mappingIndexLDPC = wlan.internal.getToneMappingIndices(chanBW);
for i = 1:numOFDMSym
for segIdx = 1:numSeg % Frequency segmentation, if needed
% Constellation mapping, Section 22.3.10.9, IEEE Std 802.11ac-2013
mappedData(:, :, segIdx) = wlan.internal.wlanConstellationMapper( ...
parsedData((i-1)*numCBPSSI + (1:numCBPSSI).', :, segIdx), numBPSCS);
% LDPC tone mapping
mappedData(:, :, segIdx) = mappedData(mappingIndexLDPC, :, segIdx);
end
% Frequency deparsing, Section 22.3.10.9.3, IEEE Std 802.11ac-2013
ssPerUser(:,i,:) = reshape(wlan.internal.wlanSegmentDeparser( ...
mappedData, chanBW, 'Tx'), [], 1, numSS);
end
end
% STBC encoding, Section 22.3.10.9.4, IEEE Std 802.11ac-2013
if numSTS>numSS
y = wlan.internal.wlanSTBCEncode(ssPerUser, numSTS);
else
y = ssPerUser;
end
end