MATLAB Examples

cdma2000 Waveform Generation

This example shows how to generate standard-compliant forward (downlink) and reverse (uplink) cdma2000® waveforms using the Communications System Toolbox™.

Contents

Introduction

The Communications System Toolbox can be used to generate preset or customized standard-compliant forward and reverse cdma2000 waveforms. Specifically, the following channels are supported:

Forward cdma2000:

  • Forward Pilot Channel (F-PICH)
  • Forward Auxiliary Pilot Channel (F-APICH)
  • Forward Transmit Diversity Pilot Channel (F-TDPICH)
  • Forward Auxiliary Transmit Diversity Pilot Channel (F-ATDPICH)
  • Forward Sync Channel (F-SYNC)
  • Forward Paging Channel (F-PCH)
  • Forward Quick Paging Channel (F-QPCH)
  • Forward Broadcast Control Channel (F-BCCH)
  • Forward Common Control Channel (F-CCCH)
  • Forward Dedicated Control Channel (F-DCCH)
  • Forward Common Power Control Channel (F-CPCCH)
  • Forward Fundamental Traffic Channel (F-FCH), including Power Control Subchannel
  • Forward Supplemental Code Channel (F-SCCH)
  • Forward Supplemental Channel (F-SCH)
  • Forward Packet Data Common Control Channel (F-PDCCH)
  • Forward Orthogonal Channel Noise (F-OCNS)

Reverse cdma2000:

  • Reverse Pilot Channel (R-PICH), including Power Control Subchannel
  • Reverse Access Channel (R-ACH)
  • Reverse Enhanced Access Channel (R-EACH)
  • Reverse Common Control Channel (R-CCCH)
  • Reverse Dedicated Control Channel (R-DCCH)
  • Reverse Fundamental Traffic Channel (R-FCH)
  • Reverse Supplemental Code Channel (R-SCCH)
  • Reverse Supplemental Channel (R-SCH)

The generated waveforms can be used for the following applications:

  • Golden reference for transmitter implementations
  • Receiver testing and algorithm development
  • Testing RF hardware and software
  • Interference testing

Waveform Generation Techniques

  • Waveforms can be generated using the cdma2000ForwardWaveformGenerator and cdma2000ReverseWaveformGenerator functions. The input of these functions is a structure containing top-level waveform parameters as well as substructures containing channel-specific parameters. This example will illustrate how such structures can be constructed from scratch.
  • Preset structure configurations can be created using the cdma2000ForwardReferenceChannels and cdma2000ReverseReferenceChannels functions. Such preset configurations can represent common Test and Measurement scenarios or provide a good starting point (wizard) for customizing a waveform configuration.

Generation of Preset-driven Forward and Reverse cdma2000 Waveforms

The preset structure configurations can then be passed to the waveform generation functions. For example, the following commands generate all forward and reverse channels allowable for Radio Configuration 4:

forwardPresetConfig     = cdma2000ForwardReferenceChannels('ALL-RC4');
forwardPresetWaveform   = cdma2000ForwardWaveformGenerator(forwardPresetConfig);

reversePresetConfig     = cdma2000ReverseReferenceChannels('ALL-RC4');
reversePresetWaveform   = cdma2000ReverseWaveformGenerator(reversePresetConfig);

Generation of a Forward cdma2000 Waveform Using Full Parameter List

Next, we illustrate the creation of equivalent configuration structures from scratch (for forward cdma2000). This is also useful for customizing the preset configurations.

fManualConfig.SpreadingRate          = 'SR1';           % Spreading Rate 1 or 3
fManualConfig.Diversity              = 'NTD';           % No Transmit Diversity (other options are 'OTD', 'STS')
fManualConfig.QOF                    = 'QOF1';          % Quasi-orthogonal function 1, 2 or 3
fManualConfig.PNOffset               = 0;               % PN offset of Base station
fManualConfig.LongCodeState          = 0;               % Initial long code state
fManualConfig.PowerNormalization     = 'Off';           % Power normalization: 'Off', 'NormalizeTo0dB' or 'NoiseFillTo0dB'
fManualConfig.OversamplingRatio      = 4;               % Upsampling factor
fManualConfig.FilterType             = 'cdma2000Long';  % Filter coefficients: 'cdma2000Long', 'cdma2000Short', 'Custom' or 'Off'
fManualConfig.InvertQ                = 'Off';           % Negate the imaginary part of the waveform
fManualConfig.EnableModulation       = 'Off';           % Enable carrier modulation
fManualConfig.ModulationFrequency    = 0;               % Modulation frequency (Hz)
fManualConfig.NumChips               = 1000;            % Number of chips in the waveform

fpich.Enable                = 'On';                     % Enable the F-PICH channel
fpich.Power                 = 0;                        % Relative channel power (dBW)
fManualConfig.FPICH         = fpich;                    % Add the channel to the waveform configuration

fapich.Enable               = 'On';                     % Enable the F-APICH channel
fapich.Power                = 0;                        % Relative channel power (dBW)
fapich.WalshCode            = 10;                       % Unique Walsh code number
fapich.WalshLength          = 64;                       % Walsh code length
fManualConfig.FAPICH        = fapich;                   % Add the channel to the waveform configuration

ftdpich.Enable              = 'On';                     % Enable the F-TDPICH channel
ftdpich.Power               = 0;                        % Relative channel power (dBW)
fManualConfig.FTDPICH       = ftdpich;                  % Add the channel to the waveform configuration

fatdpich.Enable             = 'On';                     % Enable the F-ATDPICH channel
fatdpich.Power              = 0;                        % Relative channel power (dBW)
fatdpich.WalshCode          = 11;                       % Unique Walsh code number
fatdpich.WalshLength        = 64;                       % Walsh code length
fManualConfig.FATDPICH      = fatdpich;                 % Add the channel to the waveform configuration

fpch.Enable                 = 'On';                     % Enable the F-PCH channel
fpch.Power                  = 0;                        % Relative channel power (dBW)
fpch.LongCodeMask           = 0;                        % Long code mask
fpch.DataRate               = 4800;                     % Data rate (bps)
fpch.EnableCoding           = 'On';                     % Enable channel coding
fpch.DataSource             = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
fpch.WalshCode              = 1;                        % Unique Walsh code number
fManualConfig.FPCH          = fpch;                     % Add the channel to the waveform configuration

fsync.Enable                = 'On';                     % Enable the F-SYNC channel
fsync.Power                 = 0;                        % Relative channel power (dBW)
fsync.EnableCoding          = 'On';                     % Enable channel coding
fsync.DataSource            = {'PN9', 1};               % Input message: {'PNX', Seed}, numerical vector or 'SyncMessage'
fManualConfig.FSYNC         = fsync;                    % Add the channel to the waveform configuration

fbcch.Enable                = 'On';                     % Enable the F-BCCH channel
fbcch.Power                 = 0;                        % Relative channel power (dBW)
fbcch.LongCodeMask          = 0;                        % Long code mask
fbcch.DataRate              = 4800;                     % Data rate (bps)
fbcch.FrameLength           = 160;                      % Frame length (ms)
fbcch.EnableCoding          = 'On';                     % Enable channel coding
fbcch.DataSource            = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
fbcch.WalshCode             = 2;                        % Unique Walsh code number
fbcch.CodingType            = 'conv';                   % Coding type: 'conv' or 'turbo'
fManualConfig.FBCCH         = fbcch;                    % Add the channel to the waveform configuration

fcach.Enable                = 'On';                     % Enable the F-CACH channel
fcach.Power                 = 0;                        % Relative channel power (dBW)
fcach.LongCodeMask          = 0;                        % Long code mask
fcach.EnableCoding          = 'On';                     % Enable channel coding
fcach.DataSource            = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
fcach.WalshCode             = 3;                        % Unique Walsh code number
fcach.CodingType            = 'conv';                   % Coding type: 'conv' or 'turbo'
fManualConfig.FCACH         = fcach;                    % Add the channel to the waveform configuration

fccch.Enable                = 'On';                     % Enable the F-CCCH channel
fccch.Power                 = 0;                        % Relative channel power (dBW)
fccch.LongCodeMask          = 0;                        % Long code mask
fccch.DataRate              = 9600;                     % Data rate (bps)
fccch.FrameLength           = 20;                       % Frame length (ms)
fccch.EnableCoding          = 'On';                     % Enable channel coding
fccch.DataSource            = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
fccch.WalshCode             = 4;                        % Unique Walsh code number
fccch.CodingType            = 'conv';                   % Coding type: 'conv' or 'turbo'
fManualConfig.FCCCH         = fccch;                    % Add the channel to the waveform configuration

fcpcch.Enable               = 'On';                     % Enable the F-CPCCH channel
fcpcch.Power                = 0;                        % Relative channel power (dBW)
fcpcch.LongCodeMask         = 0;                        % Long code mask
fcpcch.EnableCoding         = 'On';                     % Enable channel coding
fcpcch.DataSource           = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
fcpcch.WalshCode            = 5;                        % Unique Walsh code number
fManualConfig.FCPCCH        = fcpcch;                   % Add the channel to the waveform configuration

fqpch.Enable                = 'On';                     % Enable the F-QPCH channel
fqpch.Power                 = 0;                        % Relative channel power (dBW)
fqpch.LongCodeMask          = 0;                        % Long code mask
fqpch.DataRate              = 2400;                     % Data rate (bps)
fqpch.EnableCoding          = 'On';                     % Enable channel coding
fqpch.DataSource            = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
fqpch.WalshCode             = 6;                        % Unique Walsh code number
fManualConfig.FQPCH         = fqpch;                    % Add the channel to the waveform configuration

ffch.Enable                 = 'On';                     % Enable the F-FCH channel
ffch.Power                  = 0;                        % Relative channel power (dBW)
ffch.RadioConfiguration     = 'RC4';                    % Radio Configuration: 1-9
ffch.DataRate               = 9600;                     % Data rate (bps)
ffch.FrameLength            = 20;                       % Frame length (ms)
ffch.LongCodeMask           = 0;                        % Long code mask
ffch.EnableCoding           = 'On';                     % Enable channel coding
ffch.DataSource             = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
ffch.WalshCode              = 7;                        % Unique Walsh code number
ffch.EnableQOF              = 'Off';                    % Enable QOF spreading
ffch.PowerControlEnable     = 'Off';                    % Enable the Power Control Subchannel
fManualConfig.FFCH          = ffch;                     % Add the channel to the waveform configuration

focns.Enable                = 'On';                     % Enable the F-OCNS channel
focns.Power                 = -30;                      % Relative channel power (dBW)
focns.WalshCode              = 12;                      % Unique Walsh code number
focns.WalshLength           = 128;                      % Walsh code length
fManualConfig.FOCNS         = focns;                    % Add the channel to the waveform configuration

fdcch.Enable                = 'On';                     % Enable the F-DCCH channel
fdcch.Power                 = 0;                        % Relative channel power (dBW)
fdcch.RadioConfiguration    = 'RC4';                    % Radio Configuration: 1-9
fdcch.LongCodeMask          = 0;                        % Long code mask
fdcch.DataRate              = 9600;                     % Data rate (bps)
fdcch.FrameLength           = 5;                        % Frame length (ms)
fdcch.EnableCoding          = 'On';                     % Enable channel coding
fdcch.DataSource            = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
fdcch.WalshCode             = 8;                        % Unique Walsh code number
fdcch.EnableQOF             = 'off';                    % Enable QOF spreading
fManualConfig.FDCCH         = fdcch;                    % Add the channel to the waveform configuration

fsch.Enable                 = 'On';                     % Enable the F-SCH channel
fsch.Power                  = 0;                        % Relative channel power (dBW)
fsch.RadioConfiguration     = 'RC4';                    % Radio Configuration: 1-9
fsch.DataRate               = 9600;                     % Data rate (bps)
fsch.FrameLength            = 20;                       % Frame length (ms)
fsch.LongCodeMask           = 0;                        % Long code mask
fsch.EnableCoding           = 'On';                     % Enable channel coding
fsch.DataSource             = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
fsch.WalshCode              = 9;                        % Unique Walsh code number
fsch.EnableQOF              = 'Off';                    % Enable QOF spreading
fsch.CodingType             = 'conv';                   % Coding type: 'conv' or 'turbo'
fManualConfig.FSCH          = fsch;                     % Add the channel to the waveform configuration

forwardManualWaveform   = cdma2000ForwardWaveformGenerator(fManualConfig);

% Demonstrate that the above two parameterization approaches are equivalent:
if(isequal(forwardPresetConfig, fManualConfig))
    disp([  'Configuration structures generated with and without the ' ...
            'cdma2000ForwardReferenceChannels function are the same.']);
end
Configuration structures generated with and without the cdma2000ForwardReferenceChannels function are the same.

Generation of a Reverse cdma2000 Waveform Using Full Parameter List

rManualConfig.RadioConfiguration    = 'RC4';            % Radio Configuration: 1-6
rManualConfig.PowerNormalization    = 'Off';            % Power normalization: 'Off', 'NormalizeTo0dB' or 'NoiseFillTo0dB'
rManualConfig.OversamplingRatio     = 4;                % Upsampling factor
rManualConfig.FilterType            = 'cdma2000Long';   % Filter coefficients: 'cdma2000Long', 'cdma2000Short', 'Custom' or 'Off'
rManualConfig.InvertQ               = 'Off';            % Negate the imaginary part of the waveform
rManualConfig.EnableModulation      = 'Off';            % Enable carrier modulation
rManualConfig.ModulationFrequency   = 0;                % Modulation frequency (Hz)
rManualConfig.NumChips              = 1000;             % Number of chips in the waveform

rfch.Enable                 = 'On';                     % Enable the R-FCH channel
rfch.Power                  = 0;                        % Relative channel power (dBW)
rfch.LongCodeMask           = 0;                        % Long code mask
rfch.EnableCoding           = 'On';                     % Enable channel coding
rfch.DataSource             = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
rfch.DataRate               = 14400;                    % Data rate (bps)
rfch.FrameLength            = 20;                       % Frame length (ms)
rfch.WalshCode              = 1;                        % Unique Walsh code number
rManualConfig.RFCH          = rfch;                     % Add the channel to the waveform configuration

rpich.Enable                = 'On';                     % Enable the R-PICH channel
rpich.Power                 = 0;                        % Relative channel power (dBW)
rpich.LongCodeMask          = 0;                        % Long code mask
rpich.PowerControlEnable    = 'Off';                    % Enable the Power Control Subchannel
rManualConfig.RPICH         = rpich;                    % Add the channel to the waveform configuration

reach.Enable                = 'On';                     % Enable the R-EACH channel
reach.Power                 = 0;                        % Relative channel power (dBW)
reach.LongCodeMask          = 0;                        % Long code mask
reach.EnableCoding          = 'On';                     % Enable channel coding
reach.DataSource            = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
reach.DataRate              = 9600;                     % Data rate (bps)
reach.FrameLength           = 20;                       % Frame length (ms)
reach.WalshCode             = 2;                        % Unique Walsh code number
rManualConfig.REACH         = reach;                    % Add the channel to the waveform configuration

rcch.Enable                 = 'On';                     % Enable the R-CCH channel
rcch.Power                  = 0;                        % Relative channel power (dBW)
rcch.LongCodeMask           = 0;                        % Long code mask
rcch.EnableCoding           = 'On';                     % Enable channel coding
rcch.DataSource             = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
rcch.DataRate               = 9600;                     % Data rate (bps)
rcch.FrameLength            = 20;                       % Frame length (ms)
rcch.WalshCode              = 3;                        % Unique Walsh code number
rManualConfig.RCCCH         = rcch;                     % Add the channel to the waveform configuration

rdcch.Enable                = 'On';                     % Enable the R-DCCH channel
rdcch.Power                 = 0;                        % Relative channel power (dBW)
rdcch.LongCodeMask          = 0;                        % Long code mask
rdcch.EnableCoding          = 'On';                     % Enable channel coding
rdcch.DataSource            = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
rdcch.DataRate              = 14400;                    % Data rate (bps)
rdcch.FrameLength           = 20;                       % Frame length (ms)
rdcch.WalshCode             = 4;                        % Unique Walsh code number
rManualConfig.RDCCH         = rdcch;                    % Add the channel to the waveform configuration

rsch1.Enable                = 'On';                     % Enable the R-SCH1 channel
rsch1.Power                 = 0;                        % Relative channel power (dBW)
rsch1.LongCodeMask          = 0;                        % Long code mask
rsch1.EnableCoding          = 'On';                     % Enable channel coding
rsch1.DataSource            = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
rsch1.DataRate              = 14400;                    % Data rate (bps)
rsch1.FrameLength           = 20;                       % Frame length (ms)
rsch1.WalshLength           = 8;                        % Walsh code length
rsch1.WalshCode             = 5;                        % Unique Walsh code number
rManualConfig.RSCH1         = rsch1;                    % Add the channel to the waveform configuration

rsch2                       = rsch1;                    % Apply the same settings with R-SCH1
rsch2.WalshCode             = 6;                        % Except for the unique Walsh code number
rManualConfig.RSCH2         = rsch2;                    % Add the channel to the waveform configuration

reverseManualWaveform   = cdma2000ReverseWaveformGenerator(rManualConfig);

% Demonstrate that the above two parameterization approaches are equivalent:
if(isequal(reversePresetConfig, rManualConfig))
    disp([  'Configuration structures generated with and without the ' ...
            'cdma2000ForwardReferenceChannels function are the same.']);
end
Configuration structures generated with and without the cdma2000ForwardReferenceChannels function are the same.

Waveform Comparison

Compare the waveforms generated using both approaches described above and see that the generated waveforms are identical

if(isequal(forwardPresetWaveform, forwardManualWaveform))
    disp([  'Forward waveforms generated with and without the ' ...
            'cdma2000ForwardReferenceChannels function are the same.']);
end

if(isequal(reversePresetWaveform, reverseManualWaveform))
    disp([  'Reverse waveforms generated with and without the ' ...
            'cdma2000ReverseReferenceChannels function are the same.']);
end
Forward waveforms generated with and without the cdma2000ForwardReferenceChannels function are the same.
Reverse waveforms generated with and without the cdma2000ReverseReferenceChannels function are the same.

Customization of Configuration

The configuration structures can be customized in order to create a waveform that better suits your objective. You can also customize the preset waveforms in order to exploit additional capabilities, such as:

% 1. Specifying the message of the Sync channel:
fManualConfig2              = fManualConfig;
fsync.Enable                = 'On';                     % Enable the F-SYNC channel
fsync.Power                 = 0;                        % Relative channel power (dBW)
fsync.EnableCoding          = 'On';                     % Enable channel coding
fsync.DataSource            = 'SyncMessage';            % Input message: {'PNX', Seed}, numerical vector or 'SyncMessage'
sm.P_REV                    = 6;                        % Protocol Revision field
sm.MIN_P_REV                = 6;                        % Minimum Protocol Revision field
sm.SID                      = hex2dec('14B');           % System Identifier field
sm.NID                      = 1;                        % Network Identification field
sm.PILOT_PN                 = 0;                        % Pilot PN Offset field
sm.LC_STATE                 = hex2dec('20000000000');   % Long Code State field
sm.SYS_TIME                 = hex2dec('36AE0924C');     % System Time field
sm.LP_SEC                   = 0;                        % Leap Second field
sm.LTM_OFF                  = 0;                        % Local Time Offset field
sm.DAYLT                    = 0;                        % Daylight Savings Time Indicator field
sm.PRAT                     = 0;                        % Paging Channel Data Rate field
sm.CDMA_FREQ                = hex2dec('2F6');           % CDMA Frequency field
sm.EXT_CDMA_FREQ            = hex2dec('2F6');           % Extended CDMA Frequency field
fsync.SyncMessage           = sm;                       % Sync channel message substructure, used if 'SyncMessage' is the data source
fManualConfig2.FSYNC         = fsync;                    % Add the channel to the waveform configuration

% 2. Enabling the Power Control Subchannel of the Forward Fundamental Channel:
ffch.Enable                 = 'On';                     % Enable the F-FCH channel
ffch.Power                  = 0;                        % Relative channel power (dBW)
ffch.RadioConfiguration     = 'RC4';                    % Radio Configuration: 1-9
ffch.DataRate               = 9600;                     % Data rate (bps)
ffch.FrameLength            = 20;                       % Frame length (ms)
ffch.LongCodeMask           = 0;                        % Long code mask
ffch.EnableCoding           = 'On';                     % Enable channel coding
ffch.DataSource             = {'PN9', 1};               % Input message: {'PNX', Seed} or numerical vector
ffch.WalshCode              = 7;                        % Unique Walsh code number
ffch.EnableQOF              = 'Off';                    % Enable QOF spreading
ffch.PowerControlEnable     = 'On';                     % Enable the Power Control Subchannel
ffch.PowerControlPower      = 0;                        % Power control subchannel power (relative to F-FCH)
ffch.PowerControlDataSource = {'PN9',1};                % Power control subchannel data source
fManualConfig2.FFCH          = ffch;                     % Add the channel to the waveform configuration

forwardManualWaveform2   = cdma2000ForwardWaveformGenerator(fManualConfig2);

Plot Spectrum of Forward cdma2000 Waveform

Plot the spectrum of the time domain signal forwardManualWaveform.

chiprate                 = 1.2288e6;   % Chip rate of the baseband waveform (SR1)
fSpectrumPlot            = dsp.SpectrumAnalyzer('SampleRate', chiprate*fManualConfig.OversamplingRatio);
fSpectrumPlot.Title      = 'Spectrum of Forward cdma2000 Waveform';
fSpectrumPlot.YLimits    = [-160,40];
fSpectrumPlot(forwardManualWaveform);

Plot Spectrum of Reverse cdma2000 Waveform

Plot the spectrum of the time domain signal reverseManualWaveform.

chiprate                 = 1.2288e6;   % Chip rate of the baseband waveform (SR1)
rSpectrumPlot            = dsp.SpectrumAnalyzer('SampleRate', chiprate*rManualConfig.OversamplingRatio);
rSpectrumPlot.Title      = 'Spectrum of Reverse cdma2000 Waveform';
rSpectrumPlot.YLimits    = [-160,40];
rSpectrumPlot(reverseManualWaveform);

Selected Bibliography

  1. C.S0002-F v2.0: Physical Layer Standard for cdma2000 Spread Spectrum Systems.