NR PDSCH スループット

スクリプトを開く

この参照シミュレーションでは、3GPP NR 規格で定義されているように、5G New Radio (NR) リンクの物理ダウンリンク共有チャネル (PDSCH) のスループットを測定する方法を示します。この例では、PDSCH とダウンリンク共有チャネル (DL-SCH) を実装します。送信機モデルには、PDSCH 復調基準信号 (DM-RS) と PDSCH 位相トラッキング基準信号 (PT-RS) が含まれます。この例では、クラスター遅延線 (CDL) とタップ付き遅延線 (TDL) の両方の伝播チャネルをサポートします。完全な同期と完全なチャネル推定、あるいは実用的な同期と実用的なチャネル推定を実行できます。シミュレーションの合計時間を短縮するために、Parallel Computing Toolbox™ を使用して、SNR ループの SNR 点を並列に処理できます。

はじめに

この例では、3GPP NR 規格 [ 1 ]、[ 2 ]、[ 3 ]、[ 4 ] で定義されているように、5G リンクの PDSCH スループットを測定します。

この例では、次の 5G NR の機能をモデル化します。

DL-SCH トランスポートチャネル符号化
レイヤー数に応じた複数のコードワード
PDSCH、PDSCH DM-RS、PDSCH PT-RS の生成
可変サブキャリア間隔とフレーム numerology (2^n * 15 kHz)
ノーマルサイクリックプレフィックスと拡張サイクリックプレフィックス
TDL と CDL の伝播チャネルモデル

シミュレーションのその他の機能は、次のとおりです。

SVD を使用した PDSCH サブバンドプリコーディング
CP-OFDM 変調
スロット単位および非スロット単位での PDSCH と DM-RS のマッピング
完全な同期と完全なチャネル推定、あるいは実用的な同期と実用的なチャネル推定
16 個のプロセスを使用する HARQ 操作
この例では、キャリア全体にまたがる単一の bandwidth part を使用する

次の図は、実装される処理チェーンを示しています。わかりやすくするために、DM-RS と PT-RS の生成は省略しています。

この例で実装されている手順の詳細については、5G NR 通信リンクのモデル化とDL-SCH および PDSCH の送受信処理チェーンを参照してください。

この例では、広帯域とサブバンド両方のプリコーディングをサポートします。プリコーディング行列は、割り当て内 (広帯域の場合) またはサブバンド内のすべての PDSCH PRB でチャネル推定を平均化し、SVD を使用して決定されます。

シミュレーションの合計を短縮するために、Parallel Computing Toolbox を使用して、SNR ループの SNR 点を並列に処理できます。

シミュレーションの長さと SNR 点

シミュレーションの長さを 10 ms のフレームの数で設定します。有意なスループットの結果を得るためには、多数の NFrame を使用する必要があります。シミュレーションを行うための SNR 点を設定します。各レイヤーの SNR は RE ごとに定義され、すべてのアンテナにおいて信号とノイズの影響があります。この例で使用している SNR 定義の説明については、リンクシミュレーションで使用する SNR の定義を参照してください。

simParameters = struct();       % Clear simParameters variable to contain all key simulation parameters
simParameters.NFrames = 2;      % Number of 10 ms frames
simParameters.SNRIn = [-5 0 5]; % SNR range (dB)

チャネル推定器の構成

logical 変数 PerfectChannelEstimator は、チャネル推定と同期の動作を制御します。true に設定すると、完全なチャネル推定と同期が使用されます。それ以外の場合、受信した PDSCH DM-RS の値に基づいて、実用的なチャネル推定と同期が使用されます。

simParameters.PerfectChannelEstimator = true;

シミュレーション診断

変数 DisplaySimulationInformation は、各サブフレームに使用される HARQ プロセス ID などのシミュレーション情報の表示を制御します。CRC エラーの場合、RV シーケンスへのインデックスの値も表示されます。

simParameters.DisplaySimulationInformation = true;

DisplayDiagnostics フラグは、レイヤーごとの EVM のプロットを有効にします。このプロットは、イコライズ後の受信信号の品質を監視します。レイヤーごとの EVM の Figure は以下を表示します。

スロット単位でのレイヤーごとの EVM。これは時間とともに変化する EVM を表示します。
リソースブロック単位でのレイヤーごとの EVM。これは EVM の周波数を示します。

この Figure はシミュレーションとともに変化し、スロットごとに更新されます。通常、低い SNR またはチャネルフェージングは、信号品質の低下 (高 EVM) につながる可能性があります。チャネルは各レイヤーに異なる影響を与えるため、EVM 値はレイヤー間で異なる場合があります。

場合によっては、一部のレイヤーの EVM が他のレイヤーよりもはるかに高くなることがあります。そのような低品質のレイヤーは、CRC エラーを引き起こす可能性があります。この動作は、SNR が低いか、チャネル条件に対して使用するレイヤーが多すぎることが原因である可能性があります。この状況は、SNR を高くし、レイヤー数を減らし、アンテナ数を増やし、送信の堅牢性を高める (変調スキームとターゲット符号化率を低くする) ことを組み合わせることで回避できます。

simParameters.DisplayDiagnostics = false;

キャリアと PDSCH の構成

シミュレーションの主なパラメーターを設定します。これには、次が含まれます。

リソースブロックの帯域幅 (リソースブロックごとに 12 個のサブキャリア)。
サブキャリア間隔: 15、30、60、120 (kHz)
サイクリックプレフィックス長: normal または extended
セル ID
送信アンテナ数と受信アンテナ数

DL-SCH と PDSCH のパラメーターを含むサブ構造体も指定します。これには、次が含まれます。

ターゲット符号化率
割り当て済みリソースブロック数 (PRBSet)
変調スキーム: 'QPSK'、'16QAM'、'64QAM'、'256QAM'
レイヤーの数
PDSCH マッピングタイプ
DM-RS 構成パラメーター
PT-RS 構成パラメーター

その他のシミュレーション全体のパラメーターは、次のとおりです。

伝播チャネルモデル遅延プロファイル (TDL または CDL)

% Set waveform type and PDSCH numerology (SCS and CP type)
simParameters.Carrier = nrCarrierConfig;         % Carrier resource grid configuration
simParameters.Carrier.NSizeGrid = 51;            % Bandwidth in number of resource blocks (51 RBs at 30 kHz SCS for 20 MHz BW)
simParameters.Carrier.SubcarrierSpacing = 30;    % 15, 30, 60, 120 (kHz)
simParameters.Carrier.CyclicPrefix = 'Normal';   % 'Normal' or 'Extended' (Extended CP is relevant for 60 kHz SCS only)
simParameters.Carrier.NCellID = 1;               % Cell identity

% PDSCH/DL-SCH parameters
simParameters.PDSCH = nrPDSCHConfig;      % This PDSCH definition is the basis for all PDSCH transmissions in the BLER simulation
simParameters.PDSCHExtension = struct();  % This structure is to hold additional simulation parameters for the DL-SCH and PDSCH

% Define PDSCH time-frequency resource allocation per slot to be full grid (single full grid BWP)
simParameters.PDSCH.PRBSet = 0:simParameters.Carrier.NSizeGrid-1;                 % PDSCH PRB allocation
simParameters.PDSCH.SymbolAllocation = [0,simParameters.Carrier.SymbolsPerSlot];  % Starting symbol and number of symbols of each PDSCH allocation
simParameters.PDSCH.MappingType = 'A';     % PDSCH mapping type ('A'(slot-wise),'B'(non slot-wise))

% Scrambling identifiers
simParameters.PDSCH.NID = simParameters.Carrier.NCellID;
simParameters.PDSCH.RNTI = 1;

% PDSCH resource block mapping (TS 38.211 Section 7.3.1.6)
simParameters.PDSCH.VRBToPRBInterleaving = 0; % Disable interleaved resource mapping
simParameters.PDSCH.VRBBundleSize = 4;

% Define the number of transmission layers to be used
simParameters.PDSCH.NumLayers = 2;            % Number of PDSCH transmission layers

% Define codeword modulation and target coding rate
% The number of codewords is directly dependent on the number of layers so ensure that
% layers are set first before getting the codeword number
if simParameters.PDSCH.NumCodewords > 1                             % Multicodeword transmission (when number of layers being > 4)
    simParameters.PDSCH.Modulation = {'16QAM','16QAM'};             % 'QPSK', '16QAM', '64QAM', '256QAM'
    simParameters.PDSCHExtension.TargetCodeRate = [490 490]/1024;   % Code rate used to calculate transport block sizes
else
    simParameters.PDSCH.Modulation = '16QAM';                       % 'QPSK', '16QAM', '64QAM', '256QAM'
    simParameters.PDSCHExtension.TargetCodeRate = 490/1024;         % Code rate used to calculate transport block sizes
end

% DM-RS and antenna port configuration (TS 38.211 Section 7.4.1.1)
simParameters.PDSCH.DMRS.DMRSPortSet = 0:simParameters.PDSCH.NumLayers-1; % DM-RS ports to use for the layers
simParameters.PDSCH.DMRS.DMRSTypeAPosition = 2;      % Mapping type A only. First DM-RS symbol position (2,3)
simParameters.PDSCH.DMRS.DMRSLength = 1;             % Number of front-loaded DM-RS symbols (1(single symbol),2(double symbol))
simParameters.PDSCH.DMRS.DMRSAdditionalPosition = 2; % Additional DM-RS symbol positions (max range 0...3)
simParameters.PDSCH.DMRS.DMRSConfigurationType = 2;  % DM-RS configuration type (1,2)
simParameters.PDSCH.DMRS.NumCDMGroupsWithoutData = 1;% Number of CDM groups without data
simParameters.PDSCH.DMRS.NIDNSCID = 1;               % Scrambling identity (0...65535)
simParameters.PDSCH.DMRS.NSCID = 0;                  % Scrambling initialization (0,1)

% PT-RS configuration (TS 38.211 Section 7.4.1.2)
simParameters.PDSCH.EnablePTRS = 0;                  % Enable or disable PT-RS (1 or 0)
simParameters.PDSCH.PTRS.TimeDensity = 1;            % PT-RS time density (L_PT-RS) (1, 2, 4)
simParameters.PDSCH.PTRS.FrequencyDensity = 2;       % PT-RS frequency density (K_PT-RS) (2 or 4)
simParameters.PDSCH.PTRS.REOffset = '00';            % PT-RS resource element offset ('00', '01', '10', '11')
simParameters.PDSCH.PTRS.PTRSPortSet = [];           % PT-RS antenna port, subset of DM-RS port set. Empty corresponds to lower DM-RS port number

% Reserved PRB patterns, if required (for CORESETs, forward compatibility etc)
simParameters.PDSCH.ReservedPRB{1}.SymbolSet = [];   % Reserved PDSCH symbols
simParameters.PDSCH.ReservedPRB{1}.PRBSet = [];      % Reserved PDSCH PRBs
simParameters.PDSCH.ReservedPRB{1}.Period = [];      % Periodicity of reserved resources

% Additional simulation and DL-SCH related parameters
%
% PDSCH PRB bundling (TS 38.214 Section 5.1.2.3)
simParameters.PDSCHExtension.PRGBundleSize = [];     % 2, 4, or [] to signify "wideband"
%
% HARQ process and rate matching/TBS parameters
simParameters.PDSCHExtension.XOverhead = 6*simParameters.PDSCH.EnablePTRS; % Set PDSCH rate matching overhead for TBS (Xoh) to 6 when PT-RS is enabled, otherwise 0
simParameters.PDSCHExtension.NHARQProcesses = 16;    % Number of parallel HARQ processes to use
simParameters.PDSCHExtension.EnableHARQ = true;      % Enable retransmissions for each process, using RV sequence [0,2,3,1]

% LDPC decoder parameters
% Available algorithms: 'Belief propagation', 'Layered belief propagation', 'Normalized min-sum', 'Offset min-sum'
simParameters.PDSCHExtension.LDPCDecodingAlgorithm = 'Normalized min-sum';
simParameters.PDSCHExtension.MaximumLDPCIterationCount = 6;

% Define the overall transmission antenna geometry at end-points
% If using a CDL propagation channel then the integer number of antenna elements is
% turned into an antenna panel configured when the channel model object is created
simParameters.NTxAnts = 8;                        % Number of PDSCH transmission antennas (1,2,4,8,16,32,64,128,256,512,1024) >= NumLayers
if simParameters.PDSCH.NumCodewords > 1           % Multi-codeword transmission
    simParameters.NRxAnts = 8;                    % Number of UE receive antennas (even number >= NumLayers)
else
    simParameters.NRxAnts = 2;                    % Number of UE receive antennas (1 or even number >= NumLayers)
end

% Define data type ('single' or 'double') for resource grids and waveforms
simParameters.DataType = 'single';

% Define the general CDL/TDL propagation channel parameters
simParameters.DelayProfile = 'CDL-C';   % Use CDL-C model (Urban macrocell model)
simParameters.DelaySpread = 300e-9;
simParameters.MaximumDopplerShift = 5;

% Cross-check the PDSCH layering against the channel geometry
validateNumLayers(simParameters);

このシミュレーションは、サンプルレートなどのベースバンド波形に関するさまざまな情報に依存しています。

waveformInfo = nrOFDMInfo(simParameters.Carrier); % Get information about the baseband waveform after OFDM modulation step

伝播チャネルモデルの構築

シミュレーション用のチャネルモデルオブジェクトを作成します。CDL と TDL の両方のチャネルモデルをサポートします [ 5 ]。

% Constructed the CDL or TDL channel model object
if contains(simParameters.DelayProfile,'CDL','IgnoreCase',true)

    channel = nrCDLChannel; % CDL channel object

    % Turn the number of antennas into antenna panel array layouts. If
    % NTxAnts is not one of (1,2,4,8,16,32,64,128,256,512,1024), its value
    % is rounded up to the nearest value in the set. If NRxAnts is not 1 or
    % even, its value is rounded up to the nearest even number.
    channel = hArrayGeometry(channel,simParameters.NTxAnts,simParameters.NRxAnts);
    simParameters.NTxAnts = prod(channel.TransmitAntennaArray.Size);
    simParameters.NRxAnts = prod(channel.ReceiveAntennaArray.Size);
else
    channel = nrTDLChannel; % TDL channel object

    % Set the channel geometry
    channel.NumTransmitAntennas = simParameters.NTxAnts;
    channel.NumReceiveAntennas = simParameters.NRxAnts;
end

% Assign simulation channel parameters and waveform sample rate to the object
channel.DelayProfile = simParameters.DelayProfile;
channel.DelaySpread = simParameters.DelaySpread;
channel.MaximumDopplerShift = simParameters.MaximumDopplerShift;
channel.SampleRate = waveformInfo.SampleRate;

チャネルのマルチパス成分によって、遅延サンプルの最大数を取得します。これは、最も遅延の大きいチャネルパスとチャネルフィルターの実装遅延に基づいて計算します。これは、チャネルフィルターをフラッシュして受信信号を取得するために後で必要になります。

chInfo = info(channel);
maxChDelay = chInfo.MaximumChannelDelay;

処理ループ

各 SNR 点でのスループットを測定するために、以下の手順に従って、送信インスタンスごとの PDSCH データを解析します。

現在の HARQ プロセスの更新。提供された HARQ プロセスの送信ステータスをチェックし、再送が必要かどうかを決定します。そうでない場合は、新しいデータを生成します。
リソースグリッドの生成。nrDLSCHSystem object を呼び出して、チャネル符号化を実行します。このオブジェクトは、入力のトランスポートブロックに対して動作し、再送が必要な場合はトランスポートブロックの内部コピーを保持します。関数nrPDSCHを使用して、PDSCH の符号化ビットを変調します。次に、結果として得られた信号にプリコーディングを適用します。
波形の生成。生成されたグリッドを OFDM 変調します。
ノイズを含むチャネルのモデル化。CDL または TDL のフェージングチャネルに波形を渡します。AWGN を付加します。この例で使用している SNR 定義の説明については、リンクシミュレーションで使用する SNR の定義を参照してください。
同期と OFDM 復調の実行。完全な同期では、チャネルインパルス応答を再構築して受信波形を同期させます。実用的な同期では、受信波形と PDSCH DM-RS の相関をとります。次に、同期した信号を OFDM 復調します。
チャネル推定の実行。完全なチャネル推定では、チャネルインパルス応答を再構築して OFDM 復調を実行します。実用的なチャネル推定では、PDSCH DM-RS を使用します。
イコライズと CPE 補償の実行。推定チャネルを MMSE イコライズします。PT-RS シンボルを使用して共通位相誤差 (CPE) を推定した後、PT-RS OFDM 基準シンボルの範囲内にある各 OFDM シンボルの誤差を補正します。
プリコーディング行列の計算。特異値分解 (SVD) を使用して、次回の送信用のプリコーディング行列 W を生成します。
PDSCH の復号化。受信コードワードの推定を取得するために、関数nrPDSCHDecodeを使用して、送信アンテナと受信アンテナのすべてのペアについて復元した PDSCH シンボルを、ノイズ推定とともに復調し、デスクランブルします。
ダウンリンク共有チャネル (DL-SCH) の復号化およびブロック CRC エラーのある HARQ プロセスの更新。復号化されたソフトビットのベクトルをnrDLSCHDecoderSystem object に渡します。このオブジェクトはコードワードを復号化し、システムのスループットを判定するために使用されるブロック CRC エラーを返します。

% Array to store the maximum throughput for all SNR points
maxThroughput = zeros(length(simParameters.SNRIn),1);
% Array to store the simulation throughput for all SNR points
simThroughput = zeros(length(simParameters.SNRIn),1);

% Set up redundancy version (RV) sequence for all HARQ processes
if simParameters.PDSCHExtension.EnableHARQ
    % In the final report of RAN WG1 meeting #91 (R1-1719301), it was
    % observed in R1-1717405 that if performance is the priority, [0 2 3 1]
    % should be used. If self-decodability is the priority, it should be
    % taken into account that the upper limit of the code rate at which
    % each RV is self-decodable is in the following order: 0>3>2>1
    rvSeq = [0 2 3 1];
else
    % HARQ disabled - single transmission with RV=0, no retransmissions
    rvSeq = 0;
end

% Create DL-SCH encoder system object to perform transport channel encoding
encodeDLSCH = nrDLSCH;
encodeDLSCH.MultipleHARQProcesses = true;
encodeDLSCH.TargetCodeRate = simParameters.PDSCHExtension.TargetCodeRate;

% Create DL-SCH decoder system object to perform transport channel decoding
% Use layered belief propagation for LDPC decoding, with half the number of
% iterations as compared to the default for belief propagation decoding
decodeDLSCH = nrDLSCHDecoder;
decodeDLSCH.MultipleHARQProcesses = true;
decodeDLSCH.TargetCodeRate = simParameters.PDSCHExtension.TargetCodeRate;
decodeDLSCH.LDPCDecodingAlgorithm = simParameters.PDSCHExtension.LDPCDecodingAlgorithm;
decodeDLSCH.MaximumLDPCIterationCount = simParameters.PDSCHExtension.MaximumLDPCIterationCount;

for snrIdx = 1:numel(simParameters.SNRIn)      % comment out for parallel computing
% parfor snrIdx = 1:numel(simParameters.SNRIn) % uncomment for parallel computing
% To reduce the total simulation time, you can execute this loop in
% parallel by using the Parallel Computing Toolbox. Comment out the 'for'
% statement and uncomment the 'parfor' statement. If the Parallel Computing
% Toolbox is not installed, 'parfor' defaults to normal 'for' statement.
% Because parfor-loop iterations are executed in parallel in a
% nondeterministic order, the simulation information displayed for each SNR
% point can be intertwined. To switch off simulation information display,
% set the 'displaySimulationInformation' variable above to false

    % Reset the random number generator so that each SNR point will
    % experience the same noise realization
    rng('default');

    % Take full copies of the simulation-level parameter structures so that they are not
    % PCT broadcast variables when using parfor
    simLocal = simParameters;
    waveinfoLocal = waveformInfo;

    % Take copies of channel-level parameters to simplify subsequent parameter referencing
    carrier = simLocal.Carrier;
    pdsch = simLocal.PDSCH;
    pdschextra = simLocal.PDSCHExtension;
    decodeDLSCHLocal = decodeDLSCH;  % Copy of the decoder handle to help PCT classification of variable
    decodeDLSCHLocal.reset();        % Reset decoder at the start of each SNR point
    pathFilters = [];

    % Prepare simulation for new SNR point
    SNRdB = simLocal.SNRIn(snrIdx);
    fprintf('\nSimulating transmission scheme 1 (%dx%d) and SCS=%dkHz with %s channel at %gdB SNR for %d 10ms frame(s)\n', ...
        simLocal.NTxAnts,simLocal.NRxAnts,carrier.SubcarrierSpacing, ...
        simLocal.DelayProfile,SNRdB,simLocal.NFrames);

    % Specify the fixed order in which we cycle through the HARQ process IDs
    harqSequence = 0:pdschextra.NHARQProcesses-1;

    % Initialize the state of all HARQ processes
    harqEntity = HARQEntity(harqSequence,rvSeq,pdsch.NumCodewords);

    % Reset the channel so that each SNR point will experience the same
    % channel realization
    reset(channel);

    % Total number of slots in the simulation period
    NSlots = simLocal.NFrames * carrier.SlotsPerFrame;

    % Obtain a precoding matrix (wtx) to be used in the transmission of the
    % first transport block
    estChannelGridAnts = getInitialChannelEstimate(carrier,simLocal.NTxAnts,channel,simLocal.DataType);
    newWtx = hSVDPrecoders(carrier,pdsch,estChannelGridAnts,pdschextra.PRGBundleSize);

    % Timing offset, updated in every slot for perfect synchronization and
    % when the correlation is strong for practical synchronization
    offset = 0;

    % Loop over the entire waveform length
    for nslot = 0:NSlots-1

        % Update the carrier slot numbers for new slot
        carrier.NSlot = nslot;

        % Calculate the transport block sizes for the transmission in the slot
        [pdschIndices,pdschIndicesInfo] = nrPDSCHIndices(carrier,pdsch);
        trBlkSizes = nrTBS(pdsch.Modulation,pdsch.NumLayers,numel(pdsch.PRBSet),pdschIndicesInfo.NREPerPRB,pdschextra.TargetCodeRate,pdschextra.XOverhead);

        % HARQ processing
        for cwIdx = 1:pdsch.NumCodewords
            % If new data for current process and codeword then create a new DL-SCH transport block
            if harqEntity.NewData(cwIdx)
                trBlk = randi([0 1],trBlkSizes(cwIdx),1);
                setTransportBlock(encodeDLSCH,trBlk,cwIdx-1,harqEntity.HARQProcessID);
                % If new data because of previous RV sequence time out then flush decoder soft buffer explicitly
                if harqEntity.SequenceTimeout(cwIdx)
                    resetSoftBuffer(decodeDLSCHLocal,cwIdx-1,harqEntity.HARQProcessID);
                end
            end
        end

        % Encode the DL-SCH transport blocks
        codedTrBlocks = encodeDLSCH(pdsch.Modulation,pdsch.NumLayers, ...
            pdschIndicesInfo.G,harqEntity.RedundancyVersion,harqEntity.HARQProcessID);

        % Get precoding matrix (wtx) calculated in previous slot
        wtx = newWtx;

        % Create resource grid for a slot
        pdschGrid = nrResourceGrid(carrier,simLocal.NTxAnts,OutputDataType=simLocal.DataType);

        % PDSCH modulation and precoding
        pdschSymbols = nrPDSCH(carrier,pdsch,codedTrBlocks);
        [pdschAntSymbols,pdschAntIndices] = nrPDSCHPrecode(carrier,pdschSymbols,pdschIndices,wtx);

        % PDSCH mapping in grid associated with PDSCH transmission period
        pdschGrid(pdschAntIndices) = pdschAntSymbols;

        % PDSCH DM-RS precoding and mapping
        dmrsSymbols = nrPDSCHDMRS(carrier,pdsch);
        dmrsIndices = nrPDSCHDMRSIndices(carrier,pdsch);
        [dmrsAntSymbols,dmrsAntIndices] = nrPDSCHPrecode(carrier,dmrsSymbols,dmrsIndices,wtx);
        pdschGrid(dmrsAntIndices) = dmrsAntSymbols;

        % PDSCH PT-RS precoding and mapping
        ptrsSymbols = nrPDSCHPTRS(carrier,pdsch);
        ptrsIndices = nrPDSCHPTRSIndices(carrier,pdsch);
        [ptrsAntSymbols,ptrsAntIndices] = nrPDSCHPrecode(carrier,ptrsSymbols,ptrsIndices,wtx);
        pdschGrid(ptrsAntIndices) = ptrsAntSymbols;

        % OFDM modulation
        txWaveform = nrOFDMModulate(carrier,pdschGrid);

        % Pass data through channel model. Append zeros at the end of the
        % transmitted waveform to flush channel content. These zeros take
        % into account any delay introduced in the channel. This is a mix
        % of multipath delay and implementation delay. This value may
        % change depending on the sampling rate, delay profile and delay
        % spread
        txWaveform = [txWaveform; zeros(maxChDelay,size(txWaveform,2))]; %#ok<AGROW>
        [rxWaveform,pathGains,sampleTimes] = channel(txWaveform);

        % Add AWGN to the received time domain waveform
        % Normalize noise power by the IFFT size used in OFDM modulation,
        % as the OFDM modulator applies this normalization to the
        % transmitted waveform. Also normalize by the number of receive
        % antennas, as the channel model applies this normalization to the
        % received waveform, by default
        SNR = 10^(SNRdB/10);
        N0 = 1/sqrt(simLocal.NRxAnts*double(waveinfoLocal.Nfft)*SNR);
        noise = N0*randn(size(rxWaveform),"like",rxWaveform);
        rxWaveform = rxWaveform + noise;

        if (simLocal.PerfectChannelEstimator)
            % Perfect synchronization. Use information provided by the
            % channel to find the strongest multipath component
            pathFilters = getPathFilters(channel);
            [offset,mag] = nrPerfectTimingEstimate(pathGains,pathFilters);
        else
            % Practical synchronization. Correlate the received waveform
            % with the PDSCH DM-RS to give timing offset estimate 't' and
            % correlation magnitude 'mag'. The function
            % hSkipWeakTimingOffset is used to update the receiver timing
            % offset. If the correlation peak in 'mag' is weak, the current
            % timing estimate 't' is ignored and the previous estimate
            % 'offset' is used
            [t,mag] = nrTimingEstimate(carrier,rxWaveform,dmrsIndices,dmrsSymbols);
            offset = hSkipWeakTimingOffset(offset,t,mag);
            % Display a warning if the estimated timing offset exceeds the
            % maximum channel delay
            if offset > maxChDelay
                warning(['Estimated timing offset (%d) is greater than the maximum channel delay (%d).' ...
                    ' This will result in a decoding failure. This may be caused by low SNR,' ...
                    ' or not enough DM-RS symbols to synchronize successfully.'],offset,maxChDelay);
            end
        end
        rxWaveform = rxWaveform(1+offset:end,:);

        % Perform OFDM demodulation on the received data to recreate the
        % resource grid, including padding in the event that practical
        % synchronization results in an incomplete slot being demodulated
        rxGrid = nrOFDMDemodulate(carrier,rxWaveform);
        [K,L,R] = size(rxGrid);
        if (L < carrier.SymbolsPerSlot)
            rxGrid = cat(2,rxGrid,zeros(K,carrier.SymbolsPerSlot-L,R));
        end

        if (simLocal.PerfectChannelEstimator)
            % Perfect channel estimation, using the value of the path gains
            % provided by the channel. This channel estimate does not
            % include the effect of transmitter precoding
            estChannelGridAnts = nrPerfectChannelEstimate(carrier,pathGains,pathFilters,offset,sampleTimes);

            % Get perfect noise estimate (from the noise realization)
            noiseGrid = nrOFDMDemodulate(carrier,noise(1+offset:end ,:));
            noiseEst = var(noiseGrid(:));

            % Get PDSCH resource elements from the received grid and
            % channel estimate
            [pdschRx,pdschHest,~,pdschHestIndices] = nrExtractResources(pdschIndices,rxGrid,estChannelGridAnts);

            % Apply precoding to channel estimate
            pdschHest = nrPDSCHPrecode(carrier,pdschHest,pdschHestIndices,permute(wtx,[2 1 3]));
        else
            % Practical channel estimation between the received grid and
            % each transmission layer, using the PDSCH DM-RS for each
            % layer. This channel estimate includes the effect of
            % transmitter precoding
            [estChannelGridPorts,noiseEst] = hSubbandChannelEstimate(carrier,rxGrid,dmrsIndices,dmrsSymbols,pdschextra.PRGBundleSize,'CDMLengths',pdsch.DMRS.CDMLengths);

            % Average noise estimate across PRGs and layers
            noiseEst = mean(noiseEst,'all');

            % Get PDSCH resource elements from the received grid and
            % channel estimate
            [pdschRx,pdschHest] = nrExtractResources(pdschIndices,rxGrid,estChannelGridPorts);

            % Remove precoding from estChannelGridPorts to get channel
            % estimate w.r.t. antennas
            estChannelGridAnts = precodeChannelEstimate(carrier,estChannelGridPorts,conj(wtx));
        end

        % Equalization
        [pdschEq,csi] = nrEqualizeMMSE(pdschRx,pdschHest,noiseEst);

        % Common phase error (CPE) compensation
        if ~isempty(ptrsIndices)
            % Initialize temporary grid to store equalized symbols
            tempGrid = nrResourceGrid(carrier,pdsch.NumLayers);

            % Extract PT-RS symbols from received grid and estimated
            % channel grid
            [ptrsRx,ptrsHest,~,~,ptrsHestIndices,ptrsLayerIndices] = nrExtractResources(ptrsIndices,rxGrid,estChannelGridAnts,tempGrid);
            ptrsHest = nrPDSCHPrecode(carrier,ptrsHest,ptrsHestIndices,permute(wtx,[2 1 3]));

            % Equalize PT-RS symbols and map them to tempGrid
            ptrsEq = nrEqualizeMMSE(ptrsRx,ptrsHest,noiseEst);
            tempGrid(ptrsLayerIndices) = ptrsEq;

            % Estimate the residual channel at the PT-RS locations in
            % tempGrid
            cpe = nrChannelEstimate(tempGrid,ptrsIndices,ptrsSymbols);

            % Sum estimates across subcarriers, receive antennas, and
            % layers. Then, get the CPE by taking the angle of the
            % resultant sum
            cpe = angle(sum(cpe,[1 3 4]));

            % Map the equalized PDSCH symbols to tempGrid
            tempGrid(pdschIndices) = pdschEq;

            % Correct CPE in each OFDM symbol within the range of reference
            % PT-RS OFDM symbols
            symLoc = pdschIndicesInfo.PTRSSymbolSet(1)+1:pdschIndicesInfo.PTRSSymbolSet(end)+1;
            tempGrid(:,symLoc,:) = tempGrid(:,symLoc,:).*exp(-1i*cpe(symLoc));

            % Extract PDSCH symbols
            pdschEq = tempGrid(pdschIndices);
        end

        % Decode PDSCH physical channel
        [dlschLLRs,rxSymbols] = nrPDSCHDecode(carrier,pdsch,pdschEq,noiseEst);

        % Display EVM per layer, per slot and per RB
        if (simLocal.DisplayDiagnostics)
            plotLayerEVM(NSlots,nslot,pdsch,size(pdschGrid),pdschIndices,pdschSymbols,pdschEq);
        end

        % Scale LLRs by CSI
        csi = nrLayerDemap(csi); % CSI layer demapping
        for cwIdx = 1:pdsch.NumCodewords
            Qm = length(dlschLLRs{cwIdx})/length(rxSymbols{cwIdx}); % bits per symbol
            csi{cwIdx} = repmat(csi{cwIdx}.',Qm,1);                 % expand by each bit per symbol
            dlschLLRs{cwIdx} = dlschLLRs{cwIdx} .* csi{cwIdx}(:);   % scale by CSI
        end

        % Decode the DL-SCH transport channel
        decodeDLSCHLocal.TransportBlockLength = trBlkSizes;
        [decbits,blkerr] = decodeDLSCHLocal(dlschLLRs,pdsch.Modulation,pdsch.NumLayers,harqEntity.RedundancyVersion,harqEntity.HARQProcessID);

        % Store values to calculate throughput
        simThroughput(snrIdx) = simThroughput(snrIdx) + sum(~blkerr .* trBlkSizes);
        maxThroughput(snrIdx) = maxThroughput(snrIdx) + sum(trBlkSizes);

        % Update current process with CRC error and advance to next process
        procstatus = updateAndAdvance(harqEntity,blkerr,trBlkSizes,pdschIndicesInfo.G);
        if (simLocal.DisplaySimulationInformation)
            fprintf('\n(%3.2f%%) NSlot=%d, %s',100*(nslot+1)/NSlots,nslot,procstatus);
        end

        % Get precoding matrix for next slot
        newWtx = hSVDPrecoders(carrier,pdsch,estChannelGridAnts,pdschextra.PRGBundleSize);

     end

    % Display the results dynamically in the command window
    if (simLocal.DisplaySimulationInformation)
        fprintf('\n');
    end
    fprintf('\nThroughput(Mbps) for %d frame(s) = %.4f\n',simLocal.NFrames,1e-6*simThroughput(snrIdx)/(simLocal.NFrames*10e-3));
    fprintf('Throughput(%%) for %d frame(s) = %.4f\n',simLocal.NFrames,simThroughput(snrIdx)*100/maxThroughput(snrIdx));

end

Simulating transmission scheme 1 (8x2) and SCS=30kHz with CDL-C channel at -5dB SNR for 2 10ms frame(s)

(2.50%) NSlot=0, HARQ Proc 0: CW0: Initial transmission failed (RV=0,CR=0.474736).
(5.00%) NSlot=1, HARQ Proc 1: CW0: Initial transmission failed (RV=0,CR=0.474736).
(7.50%) NSlot=2, HARQ Proc 2: CW0: Initial transmission failed (RV=0,CR=0.474736).
(10.00%) NSlot=3, HARQ Proc 3: CW0: Initial transmission failed (RV=0,CR=0.474736).
(12.50%) NSlot=4, HARQ Proc 4: CW0: Initial transmission failed (RV=0,CR=0.474736).
(15.00%) NSlot=5, HARQ Proc 5: CW0: Initial transmission failed (RV=0,CR=0.474736).
(17.50%) NSlot=6, HARQ Proc 6: CW0: Initial transmission failed (RV=0,CR=0.474736).
(20.00%) NSlot=7, HARQ Proc 7: CW0: Initial transmission failed (RV=0,CR=0.474736).
(22.50%) NSlot=8, HARQ Proc 8: CW0: Initial transmission failed (RV=0,CR=0.474736).
(25.00%) NSlot=9, HARQ Proc 9: CW0: Initial transmission failed (RV=0,CR=0.474736).
(27.50%) NSlot=10, HARQ Proc 10: CW0: Initial transmission failed (RV=0,CR=0.474736).
(30.00%) NSlot=11, HARQ Proc 11: CW0: Initial transmission failed (RV=0,CR=0.474736).
(32.50%) NSlot=12, HARQ Proc 12: CW0: Initial transmission failed (RV=0,CR=0.474736).
(35.00%) NSlot=13, HARQ Proc 13: CW0: Initial transmission failed (RV=0,CR=0.474736).
(37.50%) NSlot=14, HARQ Proc 14: CW0: Initial transmission failed (RV=0,CR=0.474736).
(40.00%) NSlot=15, HARQ Proc 15: CW0: Initial transmission failed (RV=0,CR=0.474736).
(42.50%) NSlot=16, HARQ Proc 0: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(45.00%) NSlot=17, HARQ Proc 1: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(47.50%) NSlot=18, HARQ Proc 2: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(50.00%) NSlot=19, HARQ Proc 3: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(52.50%) NSlot=20, HARQ Proc 4: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(55.00%) NSlot=21, HARQ Proc 5: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(57.50%) NSlot=22, HARQ Proc 6: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(60.00%) NSlot=23, HARQ Proc 7: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(62.50%) NSlot=24, HARQ Proc 8: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(65.00%) NSlot=25, HARQ Proc 9: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(67.50%) NSlot=26, HARQ Proc 10: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(70.00%) NSlot=27, HARQ Proc 11: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(72.50%) NSlot=28, HARQ Proc 12: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(75.00%) NSlot=29, HARQ Proc 13: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(77.50%) NSlot=30, HARQ Proc 14: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(80.00%) NSlot=31, HARQ Proc 15: CW0: Retransmission #1 passed (RV=2,CR=0.474736).
(82.50%) NSlot=32, HARQ Proc 0: CW0: Initial transmission failed (RV=0,CR=0.474736).
(85.00%) NSlot=33, HARQ Proc 1: CW0: Initial transmission failed (RV=0,CR=0.474736).
(87.50%) NSlot=34, HARQ Proc 2: CW0: Initial transmission failed (RV=0,CR=0.474736).
(90.00%) NSlot=35, HARQ Proc 3: CW0: Initial transmission failed (RV=0,CR=0.474736).
(92.50%) NSlot=36, HARQ Proc 4: CW0: Initial transmission failed (RV=0,CR=0.474736).
(95.00%) NSlot=37, HARQ Proc 5: CW0: Initial transmission failed (RV=0,CR=0.474736).
(97.50%) NSlot=38, HARQ Proc 6: CW0: Initial transmission failed (RV=0,CR=0.474736).
(100.00%) NSlot=39, HARQ Proc 7: CW0: Initial transmission failed (RV=0,CR=0.474736).

Throughput(Mbps) for 2 frame(s) = 24.1728
Throughput(%) for 2 frame(s) = 40.0000

Simulating transmission scheme 1 (8x2) and SCS=30kHz with CDL-C channel at 0dB SNR for 2 10ms frame(s)

(2.50%) NSlot=0, HARQ Proc 0: CW0: Initial transmission passed (RV=0,CR=0.474736).
(5.00%) NSlot=1, HARQ Proc 1: CW0: Initial transmission passed (RV=0,CR=0.474736).
(7.50%) NSlot=2, HARQ Proc 2: CW0: Initial transmission passed (RV=0,CR=0.474736).
(10.00%) NSlot=3, HARQ Proc 3: CW0: Initial transmission passed (RV=0,CR=0.474736).
(12.50%) NSlot=4, HARQ Proc 4: CW0: Initial transmission passed (RV=0,CR=0.474736).
(15.00%) NSlot=5, HARQ Proc 5: CW0: Initial transmission passed (RV=0,CR=0.474736).
(17.50%) NSlot=6, HARQ Proc 6: CW0: Initial transmission passed (RV=0,CR=0.474736).
(20.00%) NSlot=7, HARQ Proc 7: CW0: Initial transmission passed (RV=0,CR=0.474736).
(22.50%) NSlot=8, HARQ Proc 8: CW0: Initial transmission passed (RV=0,CR=0.474736).
(25.00%) NSlot=9, HARQ Proc 9: CW0: Initial transmission passed (RV=0,CR=0.474736).
(27.50%) NSlot=10, HARQ Proc 10: CW0: Initial transmission passed (RV=0,CR=0.474736).
(30.00%) NSlot=11, HARQ Proc 11: CW0: Initial transmission passed (RV=0,CR=0.474736).
(32.50%) NSlot=12, HARQ Proc 12: CW0: Initial transmission passed (RV=0,CR=0.474736).
(35.00%) NSlot=13, HARQ Proc 13: CW0: Initial transmission passed (RV=0,CR=0.474736).
(37.50%) NSlot=14, HARQ Proc 14: CW0: Initial transmission passed (RV=0,CR=0.474736).
(40.00%) NSlot=15, HARQ Proc 15: CW0: Initial transmission passed (RV=0,CR=0.474736).
(42.50%) NSlot=16, HARQ Proc 0: CW0: Initial transmission passed (RV=0,CR=0.474736).
(45.00%) NSlot=17, HARQ Proc 1: CW0: Initial transmission passed (RV=0,CR=0.474736).
(47.50%) NSlot=18, HARQ Proc 2: CW0: Initial transmission passed (RV=0,CR=0.474736).
(50.00%) NSlot=19, HARQ Proc 3: CW0: Initial transmission passed (RV=0,CR=0.474736).
(52.50%) NSlot=20, HARQ Proc 4: CW0: Initial transmission passed (RV=0,CR=0.474736).
(55.00%) NSlot=21, HARQ Proc 5: CW0: Initial transmission passed (RV=0,CR=0.474736).
(57.50%) NSlot=22, HARQ Proc 6: CW0: Initial transmission passed (RV=0,CR=0.474736).
(60.00%) NSlot=23, HARQ Proc 7: CW0: Initial transmission passed (RV=0,CR=0.474736).
(62.50%) NSlot=24, HARQ Proc 8: CW0: Initial transmission passed (RV=0,CR=0.474736).
(65.00%) NSlot=25, HARQ Proc 9: CW0: Initial transmission passed (RV=0,CR=0.474736).
(67.50%) NSlot=26, HARQ Proc 10: CW0: Initial transmission passed (RV=0,CR=0.474736).
(70.00%) NSlot=27, HARQ Proc 11: CW0: Initial transmission passed (RV=0,CR=0.474736).
(72.50%) NSlot=28, HARQ Proc 12: CW0: Initial transmission passed (RV=0,CR=0.474736).
(75.00%) NSlot=29, HARQ Proc 13: CW0: Initial transmission passed (RV=0,CR=0.474736).
(77.50%) NSlot=30, HARQ Proc 14: CW0: Initial transmission passed (RV=0,CR=0.474736).
(80.00%) NSlot=31, HARQ Proc 15: CW0: Initial transmission passed (RV=0,CR=0.474736).
(82.50%) NSlot=32, HARQ Proc 0: CW0: Initial transmission passed (RV=0,CR=0.474736).
(85.00%) NSlot=33, HARQ Proc 1: CW0: Initial transmission passed (RV=0,CR=0.474736).
(87.50%) NSlot=34, HARQ Proc 2: CW0: Initial transmission passed (RV=0,CR=0.474736).
(90.00%) NSlot=35, HARQ Proc 3: CW0: Initial transmission passed (RV=0,CR=0.474736).
(92.50%) NSlot=36, HARQ Proc 4: CW0: Initial transmission passed (RV=0,CR=0.474736).
(95.00%) NSlot=37, HARQ Proc 5: CW0: Initial transmission passed (RV=0,CR=0.474736).
(97.50%) NSlot=38, HARQ Proc 6: CW0: Initial transmission passed (RV=0,CR=0.474736).
(100.00%) NSlot=39, HARQ Proc 7: CW0: Initial transmission passed (RV=0,CR=0.474736).

Throughput(Mbps) for 2 frame(s) = 60.4320
Throughput(%) for 2 frame(s) = 100.0000

Simulating transmission scheme 1 (8x2) and SCS=30kHz with CDL-C channel at 5dB SNR for 2 10ms frame(s)

(2.50%) NSlot=0, HARQ Proc 0: CW0: Initial transmission passed (RV=0,CR=0.474736).
(5.00%) NSlot=1, HARQ Proc 1: CW0: Initial transmission passed (RV=0,CR=0.474736).
(7.50%) NSlot=2, HARQ Proc 2: CW0: Initial transmission passed (RV=0,CR=0.474736).
(10.00%) NSlot=3, HARQ Proc 3: CW0: Initial transmission passed (RV=0,CR=0.474736).
(12.50%) NSlot=4, HARQ Proc 4: CW0: Initial transmission passed (RV=0,CR=0.474736).
(15.00%) NSlot=5, HARQ Proc 5: CW0: Initial transmission passed (RV=0,CR=0.474736).
(17.50%) NSlot=6, HARQ Proc 6: CW0: Initial transmission passed (RV=0,CR=0.474736).
(20.00%) NSlot=7, HARQ Proc 7: CW0: Initial transmission passed (RV=0,CR=0.474736).
(22.50%) NSlot=8, HARQ Proc 8: CW0: Initial transmission passed (RV=0,CR=0.474736).
(25.00%) NSlot=9, HARQ Proc 9: CW0: Initial transmission passed (RV=0,CR=0.474736).
(27.50%) NSlot=10, HARQ Proc 10: CW0: Initial transmission passed (RV=0,CR=0.474736).
(30.00%) NSlot=11, HARQ Proc 11: CW0: Initial transmission passed (RV=0,CR=0.474736).
(32.50%) NSlot=12, HARQ Proc 12: CW0: Initial transmission passed (RV=0,CR=0.474736).
(35.00%) NSlot=13, HARQ Proc 13: CW0: Initial transmission passed (RV=0,CR=0.474736).
(37.50%) NSlot=14, HARQ Proc 14: CW0: Initial transmission passed (RV=0,CR=0.474736).
(40.00%) NSlot=15, HARQ Proc 15: CW0: Initial transmission passed (RV=0,CR=0.474736).
(42.50%) NSlot=16, HARQ Proc 0: CW0: Initial transmission passed (RV=0,CR=0.474736).
(45.00%) NSlot=17, HARQ Proc 1: CW0: Initial transmission passed (RV=0,CR=0.474736).
(47.50%) NSlot=18, HARQ Proc 2: CW0: Initial transmission passed (RV=0,CR=0.474736).
(50.00%) NSlot=19, HARQ Proc 3: CW0: Initial transmission passed (RV=0,CR=0.474736).
(52.50%) NSlot=20, HARQ Proc 4: CW0: Initial transmission passed (RV=0,CR=0.474736).
(55.00%) NSlot=21, HARQ Proc 5: CW0: Initial transmission passed (RV=0,CR=0.474736).
(57.50%) NSlot=22, HARQ Proc 6: CW0: Initial transmission passed (RV=0,CR=0.474736).
(60.00%) NSlot=23, HARQ Proc 7: CW0: Initial transmission passed (RV=0,CR=0.474736).
(62.50%) NSlot=24, HARQ Proc 8: CW0: Initial transmission passed (RV=0,CR=0.474736).
(65.00%) NSlot=25, HARQ Proc 9: CW0: Initial transmission passed (RV=0,CR=0.474736).
(67.50%) NSlot=26, HARQ Proc 10: CW0: Initial transmission passed (RV=0,CR=0.474736).
(70.00%) NSlot=27, HARQ Proc 11: CW0: Initial transmission passed (RV=0,CR=0.474736).
(72.50%) NSlot=28, HARQ Proc 12: CW0: Initial transmission passed (RV=0,CR=0.474736).
(75.00%) NSlot=29, HARQ Proc 13: CW0: Initial transmission passed (RV=0,CR=0.474736).
(77.50%) NSlot=30, HARQ Proc 14: CW0: Initial transmission passed (RV=0,CR=0.474736).
(80.00%) NSlot=31, HARQ Proc 15: CW0: Initial transmission passed (RV=0,CR=0.474736).
(82.50%) NSlot=32, HARQ Proc 0: CW0: Initial transmission passed (RV=0,CR=0.474736).
(85.00%) NSlot=33, HARQ Proc 1: CW0: Initial transmission passed (RV=0,CR=0.474736).
(87.50%) NSlot=34, HARQ Proc 2: CW0: Initial transmission passed (RV=0,CR=0.474736).
(90.00%) NSlot=35, HARQ Proc 3: CW0: Initial transmission passed (RV=0,CR=0.474736).
(92.50%) NSlot=36, HARQ Proc 4: CW0: Initial transmission passed (RV=0,CR=0.474736).
(95.00%) NSlot=37, HARQ Proc 5: CW0: Initial transmission passed (RV=0,CR=0.474736).
(97.50%) NSlot=38, HARQ Proc 6: CW0: Initial transmission passed (RV=0,CR=0.474736).
(100.00%) NSlot=39, HARQ Proc 7: CW0: Initial transmission passed (RV=0,CR=0.474736).

Throughput(Mbps) for 2 frame(s) = 60.4320
Throughput(%) for 2 frame(s) = 100.0000

結果

測定したスループットを表示します。これは、使用可能なリソースを所与とするリンクの最大スループットがデータ伝送に占める割合として計算されます。

figure;
plot(simParameters.SNRIn,simThroughput*100./maxThroughput,'o-.')
xlabel('SNR (dB)'); ylabel('Throughput (%)'); grid on;
title(sprintf('%s (%dx%d) / NRB=%d / SCS=%dkHz', ...
              simParameters.DelayProfile,simParameters.NTxAnts,simParameters.NRxAnts, ...
              simParameters.Carrier.NSizeGrid,simParameters.Carrier.SubcarrierSpacing));

% Bundle key parameters and results into a combined structure for recording
simResults.simParameters = simParameters;
simResults.simThroughput = simThroughput;
simResults.maxThroughput = maxThroughput;

次の Figure は、10,000 サブフレーム (NFrames = 1000、SNRIn = -18:2:16) のシミュレーションで取得したスループットの結果を示しています。

参考文献

3GPP TS 38.211. "NR; Physical channels and modulation." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.
3GPP TS 38.212. "NR; Multiplexing and channel coding." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.
3GPP TS 38.213. "NR; Physical layer procedures for control." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.
3GPP TS 38.214. "NR; Physical layer procedures for data." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.
3GPP TR 38.901. "Study on channel model for frequencies from 0.5 to 100 GHz." 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.

ローカル関数

function validateNumLayers(simParameters)
% Validate the number of layers, relative to the antenna geometry

    numlayers = simParameters.PDSCH.NumLayers;
    ntxants = simParameters.NTxAnts;
    nrxants = simParameters.NRxAnts;
    antennaDescription = sprintf('min(NTxAnts,NRxAnts) = min(%d,%d) = %d',ntxants,nrxants,min(ntxants,nrxants));
    if numlayers > min(ntxants,nrxants)
        error('The number of layers (%d) must satisfy NumLayers <= %s', ...
            numlayers,antennaDescription);
    end

    % Display a warning if the maximum possible rank of the channel equals
    % the number of layers
    if (numlayers > 2) && (numlayers == min(ntxants,nrxants))
        warning(['The maximum possible rank of the channel, given by %s, is equal to NumLayers (%d).' ...
            ' This may result in a decoding failure under some channel conditions.' ...
            ' Try decreasing the number of layers or increasing the channel rank' ...
            ' (use more transmit or receive antennas).'],antennaDescription,numlayers); %#ok<SPWRN>
    end

end

function estChannelGrid = getInitialChannelEstimate(carrier,nTxAnts,propchannel,dataType)
% Obtain channel estimate before first transmission. This can be used to
% obtain a precoding matrix for the first slot.

    ofdmInfo = nrOFDMInfo(carrier);

    chInfo = info(propchannel);
    maxChDelay = chInfo.MaximumChannelDelay;

    % Temporary waveform (only needed for the sizes)
    tmpWaveform = zeros((ofdmInfo.SampleRate/1000/carrier.SlotsPerSubframe)+maxChDelay,nTxAnts,dataType);

    % Filter through channel
    [~,pathGains,sampleTimes] = propchannel(tmpWaveform);

    % Perfect timing synch
    pathFilters = getPathFilters(propchannel);
    offset = nrPerfectTimingEstimate(pathGains,pathFilters);

    % Perfect channel estimate
    estChannelGrid = nrPerfectChannelEstimate(carrier,pathGains,pathFilters,offset,sampleTimes);

end

function estChannelGrid = precodeChannelEstimate(carrier,estChannelGrid,W)
% Apply precoding matrix W to the last dimension of the channel estimate

    [K,L,R,P] = size(estChannelGrid);
    estChannelGrid = reshape(estChannelGrid,[K*L R P]);
    estChannelGrid = nrPDSCHPrecode(carrier,estChannelGrid,reshape(1:numel(estChannelGrid),[K*L R P]),W);
    estChannelGrid = reshape(estChannelGrid,K,L,R,[]);

end

function plotLayerEVM(NSlots,nslot,pdsch,siz,pdschIndices,pdschSymbols,pdschEq)
% Plot EVM information

    persistent slotEVM;
    persistent rbEVM
    persistent evmPerSlot;

    if (nslot==0)
        slotEVM = comm.EVM;
        rbEVM = comm.EVM;
        evmPerSlot = NaN(NSlots,pdsch.NumLayers);
        figure;
    end
    evmPerSlot(nslot+1,:) = slotEVM(pdschSymbols,pdschEq);
    subplot(2,1,1);
    plot(0:(NSlots-1),evmPerSlot,'o-');
    xlabel('Slot number');
    ylabel('EVM (%)');
    legend("layer " + (1:pdsch.NumLayers),'Location','EastOutside');
    title('EVM per layer per slot');

    subplot(2,1,2);
    [k,~,p] = ind2sub(siz,pdschIndices);
    rbsubs = floor((k-1) / 12);
    NRB = siz(1) / 12;
    evmPerRB = NaN(NRB,pdsch.NumLayers);
    for nu = 1:pdsch.NumLayers
        for rb = unique(rbsubs).'
            this = (rbsubs==rb & p==nu);
            evmPerRB(rb+1,nu) = rbEVM(pdschSymbols(this),pdschEq(this));
        end
    end
    plot(0:(NRB-1),evmPerRB,'x-');
    xlabel('Resource block');
    ylabel('EVM (%)');
    legend("layer " + (1:pdsch.NumLayers),'Location','EastOutside');
    title(['EVM per layer per resource block, slot #' num2str(nslot)]);

    drawnow;

end