5G NR Uplink Carrier Waveform Generation

This example implements a 5G NR uplink carrier waveform generator using 5G Toolbox™.

Introduction

This example shows how to parameterize and generate a 5G New Radio (NR) uplink waveform. The following channels and signals can be generated:

  • PUSCH and its associated DM-RS and PT-RS

  • PUCCH and its associated DM-RS

  • SRS

This example supports the parameterization and generation of multiple bandwidth parts (BWP). Multiple instances of PUSCH, PUCCH and SRS can be generated over the different BWPs. The example allows to configure PUCCH, PUSCH and SRS for a specific UE categorized by RNTI and transmits only PUSCH for that specific RNTI when both PUCCH and PUSCH overlap in a slot.

Waveform and Carrier Configuration

This section sets the subcarrier spacing (SCS) specific carrier bandwidths in resource blocks, the physical layer cell identity NCellID, and the length of the generated waveform in subframes. You can visualize the generated resource grids by setting the DisplayGrids field to 1. The channel bandwidth and frequency range parameters are used to display the associated minimum guardbands on a schematic diagram of the SCS carrier alignment. The schematic diagram is displayed in one of the output plots of the example.

waveconfig = [];
waveconfig.NCellID = 0;            % Cell identity
waveconfig.ChannelBandwidth = 50;  % Channel bandwidth (MHz)
waveconfig.FrequencyRange = 'FR1'; % 'FR1' or 'FR2'
waveconfig.NumSubframes = 10;      % Number of 1ms subframes in generated waveform
                                   % (1,2,4,8 slots per 1ms subframe,
                                   % depending on SCS)
waveconfig.DisplayGrids = 1;       % Display the resource grids after signal generation

% Define a set of SCS specific carriers, using the maximum sizes for a 50
% MHz NR channel. See TS 38.101-1 for more information on defined
% bandwidths
carriers = [];
carriers(1).SubcarrierSpacing = 15;
carriers(1).NRB = 270;
carriers(1).RBStart = 0;

carriers(2).SubcarrierSpacing = 30;
carriers(2).NRB = 133;
carriers(2).RBStart = 1;

Bandwidth Parts

A BWP is formed by a set of contiguous resources sharing a numerology on a given SCS specific carrier. This example supports the use of multiple BWPs using a struct array. Each entry in the array represents a BWP. For each BWP you can specify the subcarrier spacing (SCS), the cyclic prefix (CP) length and the bandwidth. The SubcarrierSpacing parameter maps the BWP to one of the SCS specific carriers defined earlier. The RBOffset parameter controls the location of the BWP in the carrier. This is expressed in terms of the BWP numerology. Different BWPs can overlap with each other.

% Bandwidth parts configurations
bwp = [];

bwp(1).SubcarrierSpacing = 15;              % BWP1 Subcarrier Spacing
bwp(1).CyclicPrefix = 'Normal';             % BWP1 cyclic prefix
bwp(1).NRB = 25;                            % Size of BWP1
bwp(1).RBOffset = 10;                       % Position of BWP1 in carrier

bwp(2).SubcarrierSpacing = 30;              % BWP2 Subcarrier Spacing
bwp(2).CyclicPrefix = 'Normal';             % BWP2 cyclic prefix
bwp(2).NRB = 51;                            % Size of BWP2
bwp(2).RBOffset = 40;                       % Position of BWP2 in carrier

PUCCH Instances Configuration

This section specifies the parameters for the set of PUCCH instances in the waveform. Each element in the structure array defines a PUCCH sequence instance. The following parameters can be set:

  • Enable/disable the PUCCH sequence

  • Specify the BWP carrying the PUCCH

  • PUCCH instance power in dB

  • Slots within a period used for PUCCH

  • Periodicity of the allocation. Use empty to indicate no repetition

  • DM-RS power boosting in dB

pucch = [];
pucch(1).Enable = 1;                        % Enable PUCCH sequence
pucch(1).BWP = 1;                           % Bandwidth part
pucch(1).Power = 0;                         % Power scaling in dB
pucch(1).AllocatedSlots = [3 4];            % Allocated slots within a period
pucch(1).AllocatedPeriod = 6;               % Allocation slot period (empty implies no repetition)
pucch(1).PowerDMRS = 1;                     % Additional power boosting in dB

PUCCH Resource Configuration

This section specifies the PUCCH sequence resource related parameters. The parameters can be categorized into the following sections:

  • Enable/Disable the PUCCH dedicated resource. If this is disabled, it uses common resource as per TS 38.213 Section 9.2.1

  • Provide the resource index value (0...15), when dedicated resource is disabled and the cyclic prefix of BWP transmitting PUCCH is normal. In this case, the resource and format parameters for the PUCCH transmission are filled up directly based on the resource index. All the other parameters that are provided for resource and format configurations are not considered.

When the dedicated resource is enabled or when the dedicated resource is disabled with the cyclic prefix of BWP transmitting PUCCH is extended, the following resource parameters need to be provided:

  • Specify the index of first PRB prior to frequency hopping or for no frequency hopping within the BWP

  • Specify the index of first PRB after frequency hopping within the BWP

  • Intra-slot frequency hopping configuration ('enabled','disabled')

  • Group hopping configuration ('neither','enable','disable')

and the following format specific parameters need to be provided:

  • PUCCH format configuration in the resource (0...4)

  • Starting symbol index allocated for PUCCH transmission

  • Number of OFDM symbols allocated for PUCCH transmission. For PUCCH formats 1, 3 and 4, the number of OFDM symbols allocated are in range 4 to 14, and for formats 0 and 2, it is either 1 or 2

  • Initial cyclic shift for formats 0 and 1. The value is in range 0 to 11

  • Modulation scheme for formats 3 and 4 ('QPSK','pi/2-BPSK')

  • Number of resource blocks allocated for format 2 and 3. The nominal value is one of the set {1,2,3,4,5,6,8,9,10,12,15,16}

  • Spreading factor for format 4. The value is either 2 or 4

  • Orthogonal cover code index for formats 1 and 4. For format 1, the value is in range 0 to 6. For format 4, the value is less than spreading factor and greater than or equal to 0

  • Indicate the presence of additional DM-RS for formats 3 and 4. The value is either 0 or 1

Scrambling identities to be used for different formats

  • RNTI for formats 2/3/4. It is used for sequence generation. It is in range 0 to 65535

  • Scrambling identity (NID) for PUCCH formats 2/3/4. It is in range 0 to 1023. Use empty ([]) to use physical layer cell identity. It is used in sequence generation. This parameter is provided by higher-layer parameter dataScramblingIdentityPUSCH

  • PUCCH hopping identity for formats 0/1/3/4. Use empty ([]) to use physical layer cell identity. The value is used in sequence generation for format 0, both sequence and DM-RS generation for format 1 and only for DM-RS generation for formats 3 and 4

  • DM-RS scrambling NID for PUCCH format 2. It is in range 0 to 65535. Use empty ([]) to use physical layer cell identity

Irrespective of dedicated resource configuration, the following parameters are to be provided for slot repetitions:

  • Specify the number of slot repetitions for formats 1,3,4 (2 or 4 or 8). For no slot repetition, the value can be specified as 1

  • Specify the inter-slot frequency hopping for formats 1,3,4 ('enabled','disabled'). If this is enabled and the number of slot repetitions is more than one, then intra-slot frequency hopping is disabled

  • Specify the maximum code rate. The nominal value is one of the set {0.08, 0.15, 0.25, 0.35, 0.45, 0.6, 0.8}

% Dedicated resource parameters
pucch(1).DedicatedResource = 1;             % Enable/disable the dedicated resource configuration (1/0)
% Provide the resource index value when dedicated resource is disabled. The
% PUCCH resource is configured based on the resource index value, as per
% the table 9.2.1-1 of Section 9.2.1, TS 38.213.
pucch(1).ResourceIndex = 0;                 % Resource index for PUCCH dedicated resource (0...15)

% When dedicated resource is enabled or when the dedicated resource is
% disabled with the cyclic prefix of BWP transmitting PUCCH is extended,
% the resource index value is ignored and the parameters specified below
% for the resource and format configurations are considered.

% Resource parameters
pucch(1).StartPRB = 0;                      % Index of first PRB prior to frequency hopping or for no frequency hopping
pucch(1).SecondHopPRB = 1;                  % Index of first PRB after frequency hopping
pucch(1).IntraSlotFreqHopping = 'enabled';  % Indication for intra-slot frequency hopping ('enabled','disabled')
pucch(1).GroupHopping = 'enable';           % Group hopping configuration ('enable','disable','neither')

% Format specific parameters
pucch(1).PUCCHFormat = 3;                   % PUCCH format 0/1/2/3/4
pucch(1).StartSymbol = 3;                   % Starting symbol index
pucch(1).NrOfSymbols = 11;                  % Number of OFDM symbols allocated for PUCCH
pucch(1).InitialCS = 3;                     % Initial cyclic shift for format 0 and 1
pucch(1).OCCI = 0;                          % Orthogonal cover code index for format 1 and 4
pucch(1).Modulation = 'QPSK';               % Modulation for format 3/4 ('pi/2-BPSK','QPSK')
pucch(1).NrOfRB = 9;                        % Number of resource blocks for format 2/3
pucch(1).SpreadingFactor = 4;               % Spreading factor for format 4, value is either 2 or 4
pucch(1).AdditionalDMRS = 1;                % Additional DM-RS (0/1) for format 3/4

% Scrambling identities of PUCCH and PUCCH DM-RS
pucch(1).RNTI = 0;                          % RNTI (0...65535) for formats 2/3/4
pucch(1).NID = 1;                           % PUCCH scrambling identity (0...1023) for formats 2/3/4
pucch(1).HoppingId = 1;                     % PUCCH hopping identity (0...1023) for formats 0/1/3/4
pucch(1).NIDDMRS = 1;                       % DM-RS scrambling identity (0...65535) for PUCCH format 2

% Multi-slot configuration parameters
pucch(1).NrOfSlots = 1;                     % Number of slots for PUCCH repetition (1/2/4/8). One for no repetition
pucch(1).InterSlotFreqHopping = 'disabled'; % Indication for inter-slot frequency hopping ('enabled','disabled'), used in PUCCH repetition

% Code rate - This parameter is used when there is multiplexing of UCI part
% 1 (HARQ-ACK, SR, CSI part 1) and UCI part 2 (CSI part 2) to get the rate
% matching lengths of each UCI part
pucch(1).MaxCodeRate = 0.15;                % Maximum code rate (0.08, 0.15, 0.25, 0.35, 0.45, 0.6, 0.8)

UCI payload configuration

Configure the UCI payload based on the format configuration

  • Enable or disable the UCI coding for formats 2/3/4

  • Number of HARQ-ACK bits. For formats 0 and 1, value can be at most 2. Set the value to 0, for no HARQ-ACK transmission

  • Number of SR bits. For formats 0 and 1, value can be at most 1. Set the value to 0, for no SR transmission

  • Number of CSI part 1 bits for formats 2/3/4. Set value to 0, for no CSI part 1 transmission

  • Number of CSI part 2 bits for formats 3/4. Set value to 0, for no CSI part 2 transmission. The value is ignored when there are no CSI part 1 bits

Note that the generator in the example transmits UCI information on PUSCH whenever there is a overlap between PUCCH and PUSCH for a specific RNTI in a BWP. The parameters to be configured for UCI transmission on PUSCH are provided in the section UCI on PUSCH. It requires the lengths of UCI and UL-SCH to be transmitted on PUSCH.

pucch(1).EnableCoding = 1;                  % Enable UCI coding
pucch(1).LenACK = 5;                        % Number of HARQ-ACK bits
pucch(1).LenSR = 5;                         % Number of SR bits
pucch(1).LenCSI1 = 10;                      % Number of CSI part 1 bits (for formats 2/3/4)
pucch(1).LenCSI2 = 10;                      % Number of CSI part 2 bits (for formats 3/4)

pucch(1).DataSource = 'PN9';                % UCI data source

% UCI message data source. You can use one of the following standard PN
% sequences: 'PN9-ITU', 'PN9', 'PN11', 'PN15', 'PN23'. The seed for the
% generator can be specified using a cell array in the form |{'PN9',seed}|.
% If no seed is specified, the generator is initialized with all ones

Specifying Multiple PUCCH Instances

A second PUCCH sequence instance is specified next using the second BWP.

% PUCCH sequence instance specific to second BWP
pucch(2) = pucch(1);
pucch(2).BWP = 2;
pucch(2).StartSymbol = 10;
pucch(2).NrOfSymbols = 2;
pucch(2).PUCCHFormat = 2;
pucch(2).AllocatedSlots = 0:2;
pucch(2).AllocatedPeriod = [];
pucch(2).RNTI = 10;

PUSCH Instances Configuration

This section specifies the set of PUSCH instances in the waveform using a struct array. This example defines two PUSCH sequence instances.

General Parameters

The following parameters are set for each instance:

  • Enable/disable this PUSCH sequence

  • Specify the BWP this PUSCH maps to. The PUSCH will use the SCS specified for this BWP

  • Power scaling in dB

  • Enable/disable the UL-SCH transport coding

  • Scrambling identity (NID) for PUSCH bits. It is in range 0 to 1023. Use empty ([]) to use physical layer cell identity

  • RNTI

  • Transform precoding (0,1). The value of 1, enables the transform precoding and the resultant waveform is DFT-s-OFDM. When the value is 0, the resultant waveform is CP-OFDM

  • Target code rate used to calculate the transport block sizes.

  • Overhead parameter. It is used to calculate the length of transport block size. It is one of the set {0, 6, 12, 18}

  • Transmission scheme ('codebook','nonCodebook'). When the transmission scheme is 'codebook', the MIMO precoding is enabled and a precoding matrix is selected based on the number of layers, number of antenna ports and the transmitted precoding matrix indicator. When the transmission is set to 'nonCodebook', an identity matrix is used, leading to no MIMO precoding

  • Modulation scheme ('pi/2-BPSK', 'QPSK', '16QAM', '64QAM', '256QAM'). Nominally, the modulation scheme 'pi/2-BPSK' is used when transform precoding is enabled

  • Number of layers (1...4). The number of layers is restricted to a maximum of 4 in uplink as there is only one code word transmission. Nominally, the number of layers is set to 1 when transform precoding is enabled

  • Number of antenna ports (1,2,4). It is used when codebook transmission is enabled. The number of antenna ports must be greater than or equal to number of layers

  • Transmitted precoding matrix indicator (0...27). It depends on the number of layers and the number of antenna ports

  • Redundancy version (RV) sequence

  • Intra-slot frequency hopping ('enabled','disabled')

  • Resource block offset for second hop. It is used when frequency (Intra-slot/Inter-slot) hopping is enabled

  • Inter-slot frequency hopping ('enabled','disabled'). If this is enabled, intra-slot frequency hopping is disabled, the starting position of resource block in the allocated PRB of PUSCH in the bandwidth part depends on the whether the slot is even-numbered or odd-numbered

  • Transport block data source. You can use one of the following standard PN sequences: 'PN9-ITU', 'PN9', 'PN11', 'PN15', 'PN23'. The seed for the generator can be specified using a cell array in the form {'PN9', seed}. If no seed is specified, the generator is initialized with all ones

pusch = [];
pusch(1).Enable = 1;                        % Enable PUSCH config
pusch(1).BWP = 1;                           % Bandwidth part
pusch(1).Power = 0;                         % Power scaling in dB
pusch(1).EnableCoding = 1;                  % Enable the UL-SCH transport coding
pusch(1).NID = 1;                           % Scrambling for data part (0...1023)
pusch(1).RNTI = 0;                          % RNTI
pusch(1).TransformPrecoding = 0;            % Transform precoding flag (0 or 1)
pusch(1).TargetCodeRate = 0.47;             % Code rate used to calculate transport block sizes
pusch(1).Xoh_PUSCH = 0;                     % Overhead. It is one of the set {0,6,12,18}

% Transmission settings
pusch(1).TxScheme = 'codebook';             % Transmission scheme ('codebook','nonCodebook')
pusch(1).Modulation = 'QPSK';               % 'pi/2-BPSK','QPSK','16QAM','64QAM','256QAM'
pusch(1).NLayers = 2;                       % Number of PUSCH layers (1...4)
pusch(1).NAntennaPorts = 4;                 % Number of antenna ports (1,2,4). It must not be less than number of layers
pusch(1).TPMI = 0;                          % Transmitted precoding matrix indicator (0...27)
pusch(1).RVSequence = [0 2 3 1];            % RV sequence to be applied cyclically across the PUSCH allocation sequence
pusch(1).IntraSlotFreqHopping = 'disabled'; % Intra-slot frequency hopping ('enabled','disabled')
pusch(1).RBOffset = 10;                     % Resource block offset for second hop

% Multi-slot transmission
pusch(1).InterSlotFreqHopping = 'enabled';  % Inter-slot frequency hopping ('enabled','disabled')

% Data source
pusch(1).DataSource = 'PN9';                % Transport block data source

Allocation

You can set the following parameters to control the PUSCH allocation.

  • PUSCH mapping type. It can be either 'A' or 'B'.

  • Symbols in a slot where the PUSCH is mapped to. It needs to be a contiguous allocation. For PUSCH mapping type 'A', the start symbol within a slot must be zero and the length can be from 4 to 14 (for normal CP) and up to 12 (for extended CP). For PUSCH mapping type 'B', the start symbol can be from any symbol in the slot

  • Slots in a frame used for the PUSCH

  • Period of the allocation in slots. If this is empty it indicates no repetition

  • The allocated PRBs are relative to the BWP

pusch(1).PUSCHMappingType = 'A';        % PUSCH mapping type ('A'(slot-wise),'B'(non slot-wise))
pusch(1).AllocatedSymbols = 0:13;       % Range of symbols in a slot
pusch(1).AllocatedSlots = [0 1];        % Allocated slots indices
pusch(1).AllocatedPeriod = 5;           % Allocation period in slots (empty implies no repetition)
pusch(1).AllocatedPRB = 0:10;           % PRB allocation

DM-RS Configuration

Set the DM-RS parameters

% DM-RS configuration (TS 38.211 section 6.4.1.1)
pusch(1).DMRSConfigurationType = 1;    % DM-RS configuration type (1,2)
pusch(1).NumCDMGroupsWithoutData = 2;  % Number of DM-RS CDM groups without data. The value can be one of the set {1,2,3}
pusch(1).PortSet = [0 2];              % DM-RS ports to use for the layers. The number of ports must be same as the number of layers
pusch(1).DMRSTypeAPosition = 2;        % Mapping type A only. First DM-RS symbol position (2,3)
pusch(1).DMRSLength = 1;               % Number of front-loaded DM-RS symbols (1(single symbol),2(double symbol))
pusch(1).DMRSAdditionalPosition = 2;   % Additional DM-RS symbol positions (max range 0...3)
pusch(1).NIDNSCID = 1;                 % Scrambling identity for CP-OFDM (0...65535). Use empty ([]) to use physical layer cell identity
pusch(1).NSCID = 0;                    % Scrambling initialization for CP-OFDM (0,1)
pusch(1).NRSID = 0;                    % Scrambling identity for DFT-s-OFDM DM-RS (0...1007). Use empty ([]) to use physical layer cell identity
pusch(1).PowerDMRS = 0;                % Additional power boosting in dB
pusch(1).GroupHopping = 'enable';      % {'enable','disable','neither'}. This parameter is used only when transform precoding is enabled

The parameter GroupHopping is used in DM-RS sequence generation when transform precoding is enabled. This can be set to

  • 'enable' to indicate the presence of group hopping. It is configured by higher-layer parameter sequenceGroupHopping

  • 'disable' to indicate the presence of sequence hopping. It is configured by higher-layer parameter sequenceHopping

  • 'neither' to indicate both group hopping and sequence hopping are not present

Note: The number of DM-RS CDM groups without data depends on the configuration type. The maximum number of DM-RS CDM groups can be 2 for DM-RS configuration type 1 and it can be 3 for DM-RS configuration type 2.

PT-RS Configuration

Set the PT-RS parameters

% PT-RS configuration (TS 38.211 section 6.4.1.2)
pusch(1).EnablePTRS = 0;            % Enable or disable the PT-RS (1 or 0)
pusch(1).PTRSTimeDensity = 1;       % Time density (L_PT-RS) of PT-RS (1,2,4)
pusch(1).PTRSFrequencyDensity = 2;  % Frequency density (K_PT-RS) of PT-RS for CP-OFDM (2,4)
pusch(1).PTRSNumSamples = 2;        % Number of PT-RS samples (NGroupSamp) for DFT-s-OFDM (2,4)
pusch(1).PTRSNumGroups = 2;         % Number of PT-RS groups (NPTRSGroup) for DFT-s-OFDM (2,4,8)
pusch(1).PTRSREOffset = '00';       % PT-RS resource element offset for CP-OFDM ('00','01','10','11')
pusch(1).PTRSPortSet = 0;           % PT-RS antenna ports must be a subset of DM-RS ports for CP-OFDM
pusch(1).PTRSNID = 0;               % PT-RS scrambling identity for DFT-s-OFDM (0...1007)
pusch(1).PowerPTRS = 0;             % Additional PT-RS power boosting in dB for CP-OFDM

% When PT-RS is enabled for CP-OFDM, the DM-RS ports must be in range from
% 0 to 3 for DM-RS configuration type 1, and in the range from 0 to 5 for
% DM-RS configuration type 2.
% When PT-RS is enabled for DFT-s-OFDM and the number of PT-RS groups is
% set to 8, the number of PT-RS samples must be set to 4.

UCI on PUSCH

The following parameters must be set to transmit UCI on PUSCH in overlapping slots:

  • Disable UL-SCH transmission on the overlapping slots of PUSCH (1/0). When set to 1, UL-SCH transmission is disabled on PUSCH. The example considers there is UL-SCH transmission all the time on PUSCH. A provision is provided to disable the UL-SCH transmission on the overlapping slots of PUSCH and PUCCH

  • BetaOffsetACK, BetaOffsetCSI1 and BetaOffsetCSI2 can be set from the tables 9.3-1, 9.3-2 TS 38.213 Section 9.3

  • ScalingFactor is provided by higher layer parameter scaling, as per TS 38.212, Section 6.3.2.4. The possible value is one of the set {0.5, 0.65, 0.8, 1}. This is used to limit the number of resource elements assigned to UCI on PUSCH

pusch(1).DisableULSCH = 1;             % Disable UL-SCH on overlapping slots of PUSCH and PUCCH
pusch(1).BetaOffsetACK = 1;            % Power factor of HARQ-ACK
pusch(1).BetaOffsetCSI1 = 2;           % Power factor of CSI part 1
pusch(1).BetaOffsetCSI2 = 2;           % Power factor of CSI part 2
pusch(1).ScalingFactor = 1;            % Scaling factor (0.5, 0.65, 0.8, 1)

Specifying Multiple PUSCH Instances

A second PUSCH sequence instance is specified next using the second BWP.

pusch(2) = pusch(1);
pusch(2).Enable = 1;
pusch(2).BWP = 2;
pusch(2).AllocatedSymbols = 0:11;
pusch(2).AllocatedSlots = [5 6 7 8];
pusch(2).AllocatedPRB = 5:10;
pusch(2).AllocatedPeriod = 10;
pusch(2).TransformPrecoding = 1;
pusch(2).IntraSlotFreqHopping = 'disabled';
pusch(2).GroupHopping = 'neither';
pusch(2).NLayers = 1;
pusch(2).PortSet = 1;
pusch(2).RNTI = 0;

SRS Instances Configuration

This section specifies the parameters for the set of SRS instances in the waveform. Each element in the structure array defines an SRS sequence instance. This example defines two SRS sequence instances that are disabled. The following parameters can be set:

  • Enable/Disable this SRS sequence

  • BWP carrying the SRS

  • Number of SRS antenna ports (1,2,4).

  • Number of OFDM symbols allocated for SRS transmission (1,2,4)

  • Starting OFDM symbol of the SRS transmission within a slot. It must be (8...13) for normal CP and (6...11) for extended CP

  • Slots within a period used for SRS transmission

  • Periodicity of the allocation. Use empty to indicate no repetition

  • Starting position of the SRS sequence in the BWP in RBs

  • Additional frequency offset from the starting position in 4-PRB blocks

  • Bandwidth and frequency hopping configuration. The occupied bandwidth depends on the parameters CSRS, BSRS, and BHop. Set BHop < BSRS to enable frequency hopping.

  • Transmission comb to specify the SRS frequency density in subcarriers (2,4)

  • Offset of the transmission comb in subcarriers

  • Cyclic shift rotating the low-PAPR base sequence. The maximum number of cyclic shifts, 8 or 12, depends on the transmission comb number, 2 or 4. For 4 SRS antenna ports, the subcarrier set allocated to the SRS in the first and third antenna ports depends on the cyclic shift.

  • Number of repeated SRS symbols within a slot. It disables frequency hopping in blocks of Repetition symbols. Set Repetition = 1 for no repetition.

  • Group or sequence hopping. It can be 'Neither', 'GroupHopping' or 'SequenceHopping'

  • Scrambling identity. It initializes the pseudo-random binary sequence when group or sequence hopping are enabled.

srs = struct();
srs(1).Enable = 0;                  % Enable SRS config
srs(1).BWP = 1;                     % BWP Index
srs(1).NumSRSPorts = 1;             % Number of SRS ports (1,2,4)
srs(1).NumSRSSymbols = 4;           % Number of SRS symbols in a slot (1,2,4)
srs(1).SymbolStart = 10;            % Time-domain position of the SRS in the slot. (8...13) for normal CP and (6...11) for extended CP
srs(1).AllocatedSlots = 2;          % Allocated slots indices
srs(1).AllocatedPeriod = 5;         % Allocation period in slots (empty implies no repetition)
srs(1).FreqStart = 0;               % Frequency position of the SRS in BWP in RBs
srs(1).NRRC = 0;                    % Additional offset from FreqStart specified in blocks of 4 PRBs (0...67)
srs(1).CSRS = 13;                   % Bandwidth configuration C_SRS (0...63). It controls the allocated bandwidth to the SRS
srs(1).BSRS = 2;                    % Bandwidth configuration B_SRS (0...3). It controls the allocated bandwidth to the SRS
srs(1).BHop = 1;                    % Frequency hopping configuration (0...3). Set BHop < BSRS to enable frequency hopping
srs(1).KTC = 2;                     % Comb number (2,4). It indicates the allocation of the SRS every KTC subcarriers
srs(1).KBarTC = 0;                  % Subcarrier offset of the SRS sequence (0...KTC-1)
srs(1).CyclicShift = 0;             % Cyclic shift number (0...NCSmax-1). NCSmax = 8 for KTC = 2 and NCSmax = 12 for KTC = 4.
srs(1).Repetition = 1;              % Repetition factor (1,2,4). It indicates the number of equal consecutive SRS symbols in a slot
srs(1).GroupSeqHopping = 'neither'; % Group or sequence hopping ('Neither', 'GroupHopping', 'GequenceHopping')
srs(1).NSRSID = 0;                  % Scrambling identity (0...1023)

Specifying Multiple SRS Instances

A second SRS sequence instance is specified next using the second BWP.

srs(2) = srs(1);
srs(2).Enable = 0;
srs(2).BWP = 2;
srs(2).NumSRSSymbols = 2;
srs(2).SymbolStart = 12;
srs(2).AllocatedSlots = [5 6 7 8];
srs(2).AllocatedPeriod = 10;
srs(2).BSRS = 0;
srs(2).BHop = 0;

Waveform Generation

This section collects all the parameters into the carrier configuration and generates the waveform.

% Collect together channel oriented parameter sets into a single
% configuration
waveconfig.Carriers = carriers;
waveconfig.BWP = bwp;
waveconfig.PUCCH = pucch;
waveconfig.PUSCH = pusch;
waveconfig.SRS = srs;

% Generate complex baseband waveform
[waveform,bwpset] = hNRUplinkWaveformGenerator(waveconfig);

The waveform generator also plots the SCS carrier alignment and the resource grids for the bandwidth parts (this is controlled by the field DisplayGrids in the carrier configuration). The following plots are generated:

  • Resource grid showing the location of the components (PUCCH, PUSCH and SRS) in each BWP. This does not plot the power of the signals, just their location in the grid

  • Schematic diagram of SCS carrier alignment with the associated guardbands

  • Generated waveform in the frequency domain for each BWP. This includes the PUCCH, PUSCH and SRS instances

The waveform generator function returns the time domain waveform and a struct array bwpset, which contains the following fields:

  • The resource grid corresponding to this BWP

  • The resource grid of the overall bandwidth containing the channels and signals in this BWP

  • An info structure with information corresponding to the BWP. The contents of this info structure for the first BWP are shown below:

disp('Information associated to BWP 1:')
disp(bwpset(1).Info)
Information associated to BWP 1:
           SamplingRate: 61440000
                   Nfft: 4096
              Windowing: 10
    CyclicPrefixLengths: [1x14 double]
          SymbolLengths: [1x14 double]
           NSubcarriers: 3240
      SubcarrierSpacing: 15
         SymbolsPerSlot: 14
       SlotsPerSubframe: 1
     SymbolsPerSubframe: 14
     SamplesPerSubframe: 61440
         SubframePeriod: 1.0000e-03
              Midpoints: [1x141 double]
          WindowOverlap: [10 10 10 10 10 10 10 10 10 10 10 10 10 10]
                     k0: 0

Note that the generated resource grid is a 3D matrix where the different planes represent the antenna ports. For the different physical channels and signals the lowest port is mapped to the first plane of the grid.

See Also

Functions

Related Topics