subroutine peakdt9(c2,nz2,nsps8,nspsd,c3,nz3,xdt)

  complex c2(0:4096-1)
  complex c3(0:4096-1)
  complex z
  real p(0:3300)
  include 'jt9sync.f90'

  p=0.
  i0=5*nspsd
  do i=0,nz2-1
     z=1.e-3*sum(c2(max(i-(nspsd-1),0):i))
     p(i0+i)=real(z)**2 + aimag(z)**2      !Integrated symbol power at freq=0
  enddo

  call getlags(nsps8,lag0,lag1,lag2)
  tsymbol=nsps8/1500.0
  dtlag=tsymbol/nspsd
  smax=0.
  lagpk=0
  do lag=lag1,lag2
     sum0=0.
     sum1=0.
     j=-nspsd
     do i=1,85
        j=j+nspsd
        if(isync(i).eq.1) then
           sum1=sum1+p(j+lag)
        else
           sum0=sum0+p(j+lag)
        endif
     enddo
     ss=(sum1/16.0)/(sum0/69.0) - 1.0
     xdt=(lag-lag0)*dtlag
     if(ss.gt.smax) then
        smax=ss
        lagpk=lag
     endif
  enddo

  xdt=(lagpk-lag0)*dtlag

  nz3=nspsd*85
  do i=0,nz3-1
     j=i+lagpk-i0-nspsd+1
     if(j.ge.0 .and. j.le.nz2) then
        c3(i)=c2(j)
     else
        c3(i)=0.
     endif
  enddo
 
  return
end subroutine peakdt9