def track(x, s):
n = len(x)
fs = s.fs
nco.mix(x, -s.carrier_f / fs, s.carrier_p)
s.carrier_p = s.carrier_p - n * s.carrier_f / fs
s.carrier_p = np.mod(s.carrier_p, 1)
cf = (s.code_f + s.carrier_f / 763.0) / fs
p_early = b1i.correlate(x, s.prn, 0, s.code_p - 0.5, cf, b1i.b1i_code(prn))
p_prompt = b1i.correlate(x, s.prn, 0, s.code_p, cf, b1i.b1i_code(prn))
p_late = b1i.correlate(x, s.prn, 0, s.code_p + 0.5, cf, b1i.b1i_code(prn))
if s.mode == 'FLL_WIDE':
fll_k = 3.0
a = p_prompt
b = s.prompt1
e = discriminator.fll_atan(a, b)
s.carrier_f = s.carrier_f + fll_k * e
s.prompt1 = p_prompt
elif s.mode == 'FLL_NARROW':
fll_k = 0.8
a = p_prompt
b = s.prompt1
e = discriminator.fll_atan(a, b)
s.carrier_f = s.carrier_f + fll_k * e
s.prompt1 = p_prompt
elif s.mode == 'PLL':
pll_k1 = 0.1
pll_k2 = 3.5
e = discriminator.pll_costas(p_prompt)
e1 = s.carrier_e1
s.carrier_f = s.carrier_f + pll_k1 * e + pll_k2 * (e - e1)
s.carrier_e1 = e
# code loop
dll_k1 = 0.00002
dll_k2 = 0.2
s.early = np.absolute(p_early)
s.prompt = np.absolute(p_prompt)
s.late = np.absolute(p_late)
if (s.late + s.early) == 0:
e = 0
else:
e = (s.late - s.early) / (s.late + s.early)
s.eml = e
e1 = s.code_e1
s.code_f = s.code_f + dll_k1 * e + dll_k2 * (e - e1)
s.code_e1 = e
s.code_p = s.code_p + n * cf
s.code_p = np.mod(s.code_p, b1i.code_length)
return p_prompt, s
def track(x, s):
n = len(x)
fs = s.fs
nco.mix(x, -s.carrier_f / fs, s.carrier_p)
s.carrier_p = s.carrier_p - n * s.carrier_f / fs
s.carrier_p = np.mod(s.carrier_p, 1)
cf = (s.code_f + s.carrier_f / 589.424) / fs
p_early = b1i.correlate(x, s.prn, 0, s.code_p - 0.5, cf, b1i.b1i_code(prn))
p_prompt = b1i.correlate(x, s.prn, 0, s.code_p, cf, b1i.b1i_code(prn))
p_late = b1i.correlate(x, s.prn, 0, s.code_p + 0.5, cf, b1i.b1i_code(prn))
if s.mode == "FLL_WIDE":
fll_k = 2.0
a = p_prompt
b = s.prompt1
e = discriminator.fll_atan(a, b)
s.carrier_f = s.carrier_f + fll_k * e
s.prompt1 = p_prompt
elif s.mode == "FLL_NARROW":
fll_k = 0.3
a = p_prompt
b = s.prompt1
e = discriminator.fll_atan(a, b)
s.carrier_f = s.carrier_f + fll_k * e
s.prompt1 = p_prompt
elif s.mode == "PLL":
pll_k1 = 0.1
pll_k2 = 5.0
e = discriminator.pll_costas(p_prompt)
e1 = s.carrier_e1
s.carrier_f = s.carrier_f + pll_k1 * e + pll_k2 * (e - e1)
s.carrier_e1 = e
# code loop
dll_k1 = 0.00002
dll_k2 = 0.2
s.early = np.absolute(p_early)
s.prompt = np.absolute(p_prompt)
s.late = np.absolute(p_late)
if (s.late + s.early) == 0:
e = 0
else:
e = (s.late - s.early) / (s.late + s.early)
s.eml = e
e1 = s.code_e1
s.code_f = s.code_f + dll_k1 * e + dll_k2 * (e - e1)
s.code_e1 = e
s.code_p = s.code_p + n * cf
s.code_p = np.mod(s.code_p, b1i.code_length)
return p_prompt, s