def search(x,chan):
fs = 16384000.0
n = 16384
incr = float(ca.code_length)/n
c = ca.code(0,0,incr,n) # obtain samples of the C/A code
c = fft.fft(c)
m_metric,m_code,m_doppler = 0,0,0
for doppler in np.arange(-5000,5000,200): # doppler bins
q = np.zeros(n)
w = nco.nco(-(437500*chan+doppler)/fs,0,n)
for block in range(80): # 80 incoherent sums
b = x[(block*n):((block+1)*n)]
b = b*w
r = fft.ifft(c*np.conj(fft.fft(b)))
q = q + np.absolute(r)
idx = np.argmax(q)
if q[idx]>m_metric:
m_metric = q[idx]
m_code = ca.code_length*(float(idx)/n)
m_doppler = doppler
return m_metric,m_code,m_doppler
def search(x,chan):
fs = 16384000.0
n = 16384
incr = float(ca.code_length)/n
c = ca.code(0,0,incr,n) # obtain samples of the C/A code
c = fft.fft(c)
m_metric,m_code,m_doppler = 0,0,0
for doppler in np.arange(-5000,5000,200): # doppler bins
q = np.zeros(n)
w = nco.nco(-(437500*chan+doppler)/fs,0,n)
for block in range(80): # 80 incoherent sums
b = x[(block*n):((block+1)*n)]
b = b*w
r = fft.ifft(c*np.conj(fft.fft(b)))
q = q + np.absolute(r)
idx = np.argmax(q)
if q[idx]>m_metric:
m_metric = q[idx]
m_code = ca.code_length*(float(idx)/n)
m_doppler = doppler
return m_metric,m_code,m_doppler