dvbsPLHeaderRecover
Description
recovers the physical layer (PL) signaling information from the PL header
phyparams
= dvbsPLHeaderRecover(rxplheader
,Mode
=mode)rxplheader
of the Digital Video Broadcasting Satellite Second
Generation (DVB-S2) or Digital Video Broadcasting Satellite Second Generation extended
(DVB-S2X) frame. The function uses the specified mode of operation Mode
for PL header recovery and outputs the decoded parameters
phyparams
.
Examples
Recover Physical Layer Information for DVB-S2 Frame
Recover physical layer (PL) signaling information for a given DVB-S2 frame.
Load a MAT file containing DVB-S2 LDPC parity matrices. If the MAT file is not available on the MATLAB® path, use these commands to download and unzip the MAT file.
if ~exist('dvbs2xLDPCParityMatrices.mat','file') if ~exist('s2xLDPCParityMatrices.zip','file') url = 'https://ssd.mathworks.com/supportfiles/spc/satcom/DVB/s2xLDPCParityMatrices.zip'; websave('s2xLDPCParityMatrices.zip',url); unzip('s2xLDPCParityMatrices.zip'); end addpath('s2xLDPCParityMatrices'); end
Specify the number of PL frames per stream.
nFrames = 2;
Create bit vector of information bits, data
, of concatenated TS UPs.
s2WaveGen = dvbs2WaveformGenerator; syncBits = [0 1 0 0 0 1 1 1]'; % Sync byte for TS packet is 47 Hex pktLen = 1496; % UP length without sync bits is 1496 numPkts = s2WaveGen.MinNumPackets*nFrames; txRawPkts = randi([0 1],pktLen,numPkts); txPkts = [repmat(syncBits,1,numPkts); txRawPkts]; data = txPkts(:);
Generate the DVB-S2 time-domain waveform using the input information bits. Flush the transmit filter to handle the filter delay and recover the complete last frame.
txWaveform = [s2WaveGen(data); flushFilter(s2WaveGen)];
Add additive white Gaussian noise (AWGN) to the generated waveform.
sps = s2WaveGen.SamplesPerSymbol;
EsNodB = 1;
snrdB = EsNodB - 10*log10(sps);
rxIn = awgn(txWaveform,snrdB,"measured");
Create a raised cosine receiver filter.
rxFilter = comm.RaisedCosineReceiveFilter( ... RolloffFactor=s2WaveGen.RolloffFactor, ... InputSamplesPerSymbol=sps, ... DecimationFactor=sps); s = coeffs(rxFilter); rxFilter.Gain = sum(s.Numerator);
Apply matched filtering and remove the filter delay.
filtOut = rxFilter(rxIn); rxFrame = filtOut(rxFilter.FilterSpanInSymbols+1:end);
Recover the PL information using the PL header of length 90 symbols.
headerStartIndex = 1; headerEndIndex = 90; rxPLHeader = rxFrame(headerStartIndex:headerEndIndex); phyParams = dvbsPLHeaderRecover(rxPLHeader(:), ... Mode="DVB-S2/S2X regular")
phyParams = struct with fields:
ModulationOrder: 4
FECFrameLength: 64800
LDPCCodeIdentifier: "1/4"
PLSDecimalCode: 4
TimeSlicingNumber: -1
CanonicalMODCODName: ""
HasPilots: 0
IsDummyFrame: 0
Recover Physical Layer Information for DVB-S2X Wideband Frame
Recover PL signaling information for a given DVB-S2X wideband frame.
Load a MAT file containing DVB-S2X LDPC parity matrices. If the MAT file is not available on the MATLAB path, use these commands to download and unzip the MAT file.
if ~exist('dvbs2xLDPCParityMatrices.mat','file') if ~exist('s2xLDPCParityMatrices.zip','file') url = 'https://ssd.mathworks.com/supportfiles/spc/satcom/DVB/s2xLDPCParityMatrices.zip'; websave('s2xLDPCParityMatrices.zip',url); unzip('s2xLDPCParityMatrices.zip'); end addpath('s2xLDPCParityMatrices'); end
Specify the number of PL frames per stream. Create a DVB-S2X System object™ and set its properties.
nFramesPerStream = 1; s2xWaveGen = dvbs2xWaveformGenerator(NumInputStreams=5, ... PLSDecimalCode=[140 132 133 141 132], ... DFL=[37168 18448 18448 37168 18448], ... StreamFormat="GS",HasTimeSlicing=true);
Create a bit vector of information bits for each stream.
data = cell(s2xWaveGen.NumInputStreams,1); for i = 1:s2xWaveGen.NumInputStreams data{i} = randi([0 1],s2xWaveGen.DFL(i)*nFramesPerStream,1); end
Generate DVB-S2X waveform. Flush the transmit filter to handle the filter delay and recover the complete last frame.
txWaveform = [s2xWaveGen(data); flushFilter(s2xWaveGen)];
Add AWGN noise to the generated waveform.
sps = 4; % Samples per symbol EsNodB = 4; snrdB = EsNodB - 10*log10(sps); rxWaveform = awgn(txWaveform,snrdB,"measured");
Create a raised cosine receiver filter. Apply matched filtering and remove the filter delay.
rxFilter = comm.RaisedCosineReceiveFilter( ... RolloffFactor=s2xWaveGen.RolloffFactor, ... InputSamplesPerSymbol=sps,DecimationFactor=sps); s = coeffs(rxFilter); rxFilter.Gain = sum(s.Numerator); % Matched filtering and filter delay removal filtOut = rxFilter(rxWaveform); rxSymb = filtOut(rxFilter.FilterSpanInSymbols+1:end);
Recover the MODCOD and other PL signaling information for the first DVB-S2X wideband stream. Length of PL header is 180 symbols.
headerStartIndex = 1; headerEndIndex = 180; rxPLHeader = rxSymb(headerStartIndex:headerEndIndex); phyParams = dvbsPLHeaderRecover(rxPLHeader(:), ... Mode="DVB-S2X wideband")
phyParams = struct with fields:
ModulationOrder: 8
FECFrameLength: 64800
LDPCCodeIdentifier: "104/180"
PLSDecimalCode: 140
TimeSlicingNumber: 1
CanonicalMODCODName: ""
HasPilots: 0
IsDummyFrame: 0
Recover Physical Layer Information for DVB-S2X VL-SNR Frame
Recover PL signaling information for a given DVB-S2X VL-SNR frame.
Load a MAT file containing DVB-S2X LDPC parity matrices. If the MAT file is not available on the MATLAB path, use these commands to download and unzip the MAT file.
if ~exist('dvbs2xLDPCParityMatrices.mat','file') if ~exist('s2xLDPCParityMatrices.zip','file') url = 'https://ssd.mathworks.com/supportfiles/spc/satcom/DVB/s2xLDPCParityMatrices.zip'; websave('s2xLDPCParityMatrices.zip',url); unzip('s2xLDPCParityMatrices.zip'); end addpath('s2xLDPCParityMatrices'); end
Specify the number of PL frames per stream. Create DVB-S2X System object™ and set its properties.
nFrames = 1; s2xWaveGen = dvbs2xWaveformGenerator(PLSDecimalCode=129, ... CanonicalMODCODName="QPSK 2/9",DFL=14128, ... PLScramblingIndex=4);
Create a bit vector with concatenated transport streams user packets.
syncBits = [0 1 0 0 0 1 1 1]'; % Sync byte for TS packet is 47 Hex pktLen = 1496; % UP length without sync bits is 1496 numPkts = s2xWaveGen.MinNumPackets*nFrames; txRawPkts = randi([0 1],pktLen,numPkts(1)); txPkts = [repmat(syncBits,1,numPkts(1)); txRawPkts]; data = txPkts(:);
Generate a DVB-S2X VL-SNR transmit waveform. Flush the transmit filter to handle the filter delay and recover the complete last frame.
txWaveform = [s2xWaveGen(data); flushFilter(s2xWaveGen)];
Add AWGN noise to the generated waveform.
sps = 4; % Samples per symbol EsNodB = -6; snrdB = EsNodB - 10*log10(sps); rxWaveform = awgn(txWaveform,snrdB,"measured");
Create a raised cosine receiver filter. Apply matched filtering and remove the filter delay.
rxFilter = comm.RaisedCosineReceiveFilter( ... RolloffFactor=s2xWaveGen.RolloffFactor, ... InputSamplesPerSymbol=sps,DecimationFactor=sps); s = coeffs(rxFilter); rxFilter.Gain = sum(s.Numerator); % Matched filtering and filter delay removal filtOut = rxFilter(rxWaveform); rxSymb = filtOut(rxFilter.FilterSpanInSymbols+1:end);
Recover the MODCOD and other PL signaling information for the first DVB-S2X VL-SNR stream. The length of the PL header is 990 symbols.
headerStartIndex = 1; headerEndIndex = 990; rxPLHeader = rxSymb(headerStartIndex:headerEndIndex); phyParams = dvbsPLHeaderRecover(rxPLHeader(:), ... Mode="DVB-S2X vl-snr")
phyParams = struct with fields:
ModulationOrder: 4
FECFrameLength: 64800
LDPCCodeIdentifier: "2/9"
PLSDecimalCode: 129
TimeSlicingNumber: -1
CanonicalMODCODName: "QPSK 2/9"
HasPilots: 1
IsDummyFrame: 0
Input Arguments
rxplheader
— PL header to decode
column vector
PL header to decode, specified as a column vector. The specified PL header must come from a DVB-S2 or DVB-S2X frame.
When you set
rxplheader
to a length of 90 symbols andMode
to"DVB-S2/S2X regular"
,dvbsPLHeaderRecover
function assesses the header as a DVB-S2 or DVB-S2X regular mode header, or as a PL header of a noise-affected very low signal-to-noise ratio (VL-SNR) frame.When you set
rxplheader
to a length of 900 or 990 symbols andMode
to"DVB-S2X vl-snr"
,dvbsPLHeaderRecover
function assesses the header as a DVB-S2X VL-SNR frame header.When you set
rxplheader
to a length of 180 symbols andMode
to"DVB-S2X wideband"
,dvbsPLHeaderRecover
function assesses the header as a DVB-S2X wideband frame header.
Data Types: double
Mode
— Mode of operation for PL header decoding
"DVB-S2/S2X regular"
| "DVB-S2X vl-snr"
| "DVB-S2X wideband"
Mode of operation for PL header decoding, specified as "DVB-S2/S2X
regular"
, "DVB-S2X vl-snr"
, or "DVB-S2X
wideband"
.
Data Types: char
| string
Output Arguments
phyparams
— PL signaling information
structure
PL signaling information, returned as a structure with these fields.
Structure Field | Description |
---|---|
ModulationOrder | Modulation order of the forward error correction (FEC) symbols, returned as a value from the set {2, 4, 8, 16, 32, 64, 128, 256}. A value of |
FECFrameLength | Output length of the FEC encoder and input length to the low density parity-check (LDPC) decoder, in bits, returned as a value from the set {16200, 32400, 64800}. A value of |
LDPCCodeIdentifier | Output code rate of the LDPC encoder, returned as a string scalar or character array. |
PLSDecimalCode | Physical layer signaling decimal code encapsulated in the header, returned as an integer in the range [0, 255]. |
TimeSlicingNumber | Time slicing number of the wideband PL frame, returned as an integer in the range [0, 255]. This value denotes the service that the current PL frame belongs to, and identifies whether to further process the current PL frame. This field applies when you set |
CanonicalMODCODName | Canonical modulation scheme and code rate name, returned as a string scalar or character array. Valid
If the frame is not a VL-SNR frame, the output of this field is empty. This field applies when you set |
HasPilots | Pilot block indication, returned as
|
IsDummyFrame | Dummy frame indicator, returned as |
Extended Capabilities
C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.
Version History
Introduced in R2024a
See Also
Functions
Objects
Topics
- End-to-End DVB-S2 Simulation with RF Impairments and Corrections
- End-to-End DVB-S2X Simulation with RF Impairments and Corrections for Regular Frames
- End-to-End DVB-S2X Simulation with RF Impairments and Corrections for VL-SNR Frames
- End-to-End DVB-S2X Simulation with RF Impairments and Corrections in Wideband Mode
MATLAB 명령
다음 MATLAB 명령에 해당하는 링크를 클릭했습니다.
명령을 실행하려면 MATLAB 명령 창에 입력하십시오. 웹 브라우저는 MATLAB 명령을 지원하지 않습니다.
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