find_delay.m

802.15 dsss 物理协议层方针代码

% function dt=find_delay(after_channel_acq,acq_seq,piconet,datarate,sample_times,segma)
fc=find_centre_freq(piconet);
acq_length=length(acq_seq)*24;
[carrier,carrier_min,carrier_max,fs]=gaussian_trend(segma,fc,acq_length);
power=max(max(carrier))^2;
carrier_to_sample_position=floor(sample_times/2)+1;
num=1;
code=codeset(piconet,24);
decision=zeros(1,acq_length);
dm=zeros(1,length(decision));
for k=1:length(after_channel_acq)-length(carrier)-1
    temp=carrier.*after_channel_acq(k:k+length(carrier)-1);
    temp=temp/max(abs(temp));
  
    for i=1:acq_length
        for j=1:sample_times
            decision(i)=decision(i)+(temp((i-1)*3*sample_times+carrier_to_sample_position+(j-1)*sample_times));
        end
    end

    for i=1:acq_length
        if decision(i)>=1
            dm(i)=1;
        else
            if decision(i)<=-1
                dm(i)=-1;
            else
                dm(i)=0;
            end
        end

    end
    %     same(k)=sum(xor(dm,spreaded_acq));
    for i=1:acq_length/24
        decide_acq(i)=sum(dm((i-1)*24+1:i*24).*code);
        if decide_acq(i)>0
            decide_acq(i)=1;
        else
            decide_acq(i)=0;
        end
    end
    same2(k)=sum(xor(decide_acq,acq_seq));


    %     if sum(xor(decision,spreaded_acq))<=5
    %         dt(num)=k;
    %         num=num+1;
    %
    %     end
    %
    %     if sum(xor(decide_acq,acq_seq))==0
    %         dt(num)=k;
    %         num=num+1;
    %     end
end
dt=find(same2==0);