function txNDP = MU_NDP(cfgMUMIMO,guardInterval,ChannelBandwidth)
% 产生NDP
cfgNDP = wlanHESUConfig('APEPLength',0,'GuardInterval',guardInterval); % No data in an NDP
cfgNDP.ChannelBandwidth = ChannelBandwidth;
cfgNDP.NumTransmitAntennas = cfgMUMIMO.NumTransmitAntennas;
cfgNDP.NumSpaceTimeStreams = cfgMUMIMO.NumTransmitAntennas;
txNDP = wlanWaveformGenerator([],cfgNDP);
txNDP = [txNDP; zeros(50,size(txNDP,2))];
end