www.gusucode.com > wlan 源码程序 matlab案例代码 > wlan/DetectDelayed80211aPacketExample.m

    %% Detect Delayed 802.11a Packet
% Detect a received 802.11a packet that has been delayed. No channel
% impairments are added. Set the input offset to 5 and use a threshold
% setting very close to 1.

%%
% Create an non-HT configuration object. Generate the transmit waveform.
cfgNonHT = wlanNonHTConfig;

txWaveform = wlanWaveformGenerator([1;0;0;1],cfgNonHT,...
    'WindowTransitionTime',0);
%%
% Delay the signal by appending zeros at the start. Set an initial offset
% of 5 and a threshold very close to 1. Detect the delayed packet.
rxWaveform = [zeros(20,1);txWaveform];

offset = 5;
threshold = 1-10*eps;
startOffset = wlanPacketDetect(rxWaveform,...
    cfgNonHT.ChannelBandwidth,offset,threshold)

%%
% Calculate the detected packet offset by adding the returned |startOffset|
% and the input |offset|.
totalOffset = offset + startOffset
%%
% Using a threshold close to 1 and an undistorted received waveform
% increases the accuracy of the packet detect location. The detected offset
% from the first sample of the received waveform to the start of the packet
% is determined to be 20 samples.