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 / 1540.0) / fs
p_early = b1cp.correlate(x, s.prn, 0, s.code_p - 0.2, cf,
b1cp.b1cp_code(prn), b1cp.boc11)
p_prompt = b1cp.correlate(x, s.prn, 0, s.code_p, cf, b1cp.b1cp_code(prn),
b1cp.boc11)
p_late = b1cp.correlate(x, s.prn, 0, s.code_p + 0.2, cf,
b1cp.b1cp_code(prn), b1cp.boc11)
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 = 0.6
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, b1cp.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 / 2400.0) / fs
p_early = l2cl.correlate(x, s.prn, 0, s.code_p - 0.5, cf,
l2cl.l2cl_code(prn))
p_prompt = l2cl.correlate(x, s.prn, 0, s.code_p, cf, l2cl.l2cl_code(prn))
p_late = l2cl.correlate(x, s.prn, 0, s.code_p + 0.5, cf,
l2cl.l2cl_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_atan2(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) # fixme: change to pure PLL, since L2CL is a pilot
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, l2cl.code_length)
return p_prompt, s
def track(x, s, chan):
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)
rf_carrier = 1602.0 + 0.5625 * chan
scale_factor = rf_carrier / 5.11
cf = (s.code_f + s.carrier_f / scale_factor) / fs
p_early = p.correlate(x, 0, s.code_p - 0.5, cf, p.p_code())
p_prompt = p.correlate(x, 0, s.code_p, cf, p.p_code())
p_late = p.correlate(x, 0, s.code_p + 0.5, cf, p.p_code())
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 = 0.5
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
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, p.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/115.0)/fs
p_early = e5aq.correlate(x, s.prn, 0, s.code_p-0.5, cf, e5aq.e5aq_code(prn))
p_prompt = e5aq.correlate(x, s.prn, 0, s.code_p, cf, e5aq.e5aq_code(prn))
p_late = e5aq.correlate(x, s.prn, 0, s.code_p+0.5, cf, e5aq.e5aq_code(prn))
if s.mode=='FLL_WIDE':
fll_k = 3.0
a = p_prompt
b = s.prompt1
e = discriminator.fll_atan2(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_atan2(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,e5aq.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 / 243.84) / fs
p_early = p.correlate(x, 0, s.code_p - 0.5, cf, p.p_code())
p_prompt = p.correlate(x, 0, s.code_p, cf, p.p_code())
p_late = p.correlate(x, 0, s.code_p + 0.5, cf, p.p_code())
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 = 0.5
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
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, p.code_length)
return p_prompt, s
# parse command-line arguments
# example:
# ./acquire-gps-l2cm.py /dev/stdin 69984000 -127126
filename = sys.argv[1] # input data, raw file, i/q interleaved, 8 bit signed (two's complement)
fs = float(sys.argv[2]) # sampling rate, Hz
coffset = float(sys.argv[3]) # offset to L1 carrier, Hz (positive or negative)
# read first 75 ms of file
n = int(fs*0.075)
fp = open(filename,"rb")
x = io.get_samples_complex(fp,n)
# resample to 4.096 MHz
fsr = 4096000.0/fs
nco.mix(x,-coffset/fs,0)
h = scipy.signal.firwin(161,1.5e6/(fs/2),window='hanning')
x = scipy.signal.filtfilt(h,[1],x)
xr = np.interp((1/fsr)*np.arange(75*4096),np.arange(len(x)),np.real(x))
xi = np.interp((1/fsr)*np.arange(75*4096),np.arange(len(x)),np.imag(x))
x = xr+(1j)*xi
# iterate over PRNs of interest
for prn in range(1,33):
metric,code,doppler = search(x,prn)
if metric>0.0: # fixme: need a proper metric and threshold; and estimate cn0
print('prn %3d doppler % 7.1f metric %7.1f code_offset %6.1f' % (prn,doppler,metric,code))
code_p=code_offset, code_f=e5ai.chip_rate, code_i=0,
carrier_p=0, carrier_f=doppler, carrier_i=0,
mode='PLL')
block = 0
coffset_phase = 0.0
while True:
if s.code_p<e5ai.code_length/2:
n = int(fs*0.001*(e5ai.code_length-s.code_p)/e5ai.code_length)
else:
n = int(fs*0.001*(2*e5ai.code_length-s.code_p)/e5ai.code_length)
x = io.get_samples_complex(fp,n)
if x is None:
break
nco.mix(x,-coffset/fs,coffset_phase)
coffset_phase = coffset_phase - n*coffset/fs
coffset_phase = np.mod(coffset_phase,1)
p_prompt,s = track(x,s)
vars = block, np.real(p_prompt), np.imag(p_prompt), s.carrier_f, s.code_f-e5ai.chip_rate, (180/np.pi)*np.angle(p_prompt), s.early, s.prompt, s.late
print('%d %f %f %f %f %f %f %f %f' % vars)
block = block + 1
# if (block%100)==0:
# sys.stderr.write("%d\n"%block)
# if block==2000:
# s.mode = 'PLL'
block = 0
coffset_phase = 0.0
while True:
if s.code_p < ca.code_length / 2:
n = int(fs * 0.001 * (ca.code_length - s.code_p) / ca.code_length)
else:
n = int(fs * 0.001 * (2 * ca.code_length - s.code_p) / ca.code_length)
x = io.get_samples_complex(fp, n)
if x is None:
break
fm = -(coffset + 437500 * chan) / fs
nco.mix(x, fm, coffset_phase)
coffset_phase = coffset_phase + n * fm
coffset_phase = np.mod(coffset_phase, 1)
p_prompt, s = track(x, s)
vars = block, np.real(p_prompt), np.imag(
p_prompt), s.carrier_f, s.code_f - ca.chip_rate, (
180 / np.pi) * np.angle(p_prompt), s.early, s.prompt, s.late
print('%d %f %f %f %f %f %f %f %f' % vars)
block = block + 1
# if (block%100)==0:
# sys.stderr.write("%d\n"%block)
if block == 1000:
s.mode = 'FLL_NARROW'
if block == 2000:
coffset = float(args[2]) prns = util.parse_list_ranges(options.prn) doppler_search = util.parse_list_floats(options.doppler_search) ms = options.time # read first portion of file ms_pad = ms + 5 n = int(fs*0.001*ms_pad) fp = open(filename,"rb") x = io.get_samples_complex(fp,n) # resample to 8.192 MHz fsr = 8192000.0/fs nco.mix(x,-coffset/fs,0) h = scipy.signal.firwin(161,4e6/(fs/2),window='hanning') x = scipy.signal.filtfilt(h,[1],x) xr = np.interp((1/fsr)*np.arange(ms_pad*8192),np.arange(len(x)),np.real(x)) xi = np.interp((1/fsr)*np.arange(ms_pad*8192),np.arange(len(x)),np.imag(x)) x = xr+(1j)*xi # iterate (in parallel) over PRNs of interest def worker(p): x,prn = p metric,code,doppler = search(x,prn,doppler_search,ms) return 'prn %3d doppler % 7.1f metric % 7.1f code_offset %6.1f' % (prn,doppler,metric,code) import multiprocessing as mp
s = tracking_state(fs=fs, prn=prn, # initialize tracking state
code_p=code_offset, code_f=e5aq.chip_rate, code_i=0,
carrier_p=0, carrier_f=doppler, carrier_i=0,
mode='PLL')
block = 0
coffset_phase = 0.0
while True:
if s.code_p<e5aq.code_length/2:
n = int(fs*0.001*(e5aq.code_length-s.code_p)/e5aq.code_length)
else:
n = int(fs*0.001*(2*e5aq.code_length-s.code_p)/e5aq.code_length)
x = io.get_samples_complex(fp,n)
if x==None:
break
nco.mix(x,-coffset/fs,coffset_phase)
coffset_phase = coffset_phase - n*coffset/fs
coffset_phase = np.mod(coffset_phase,1)
p_prompt,s = track(x,s)
print block, np.real(p_prompt), np.imag(p_prompt), s.carrier_f, s.code_f-e5aq.chip_rate, (180/np.pi)*np.angle(p_prompt), s.early, s.prompt, s.late
block = block + 1
# if (block%100)==0:
# sys.stderr.write("%d\n"%block)
# if block==1000:
# s.mode = 'PLL'
mode='FLL_WIDE')
block = 0
coffset_phase = 0.0
while True:
if s.code_p<ca.code_length/2:
n = int(fs*0.001*(ca.code_length-s.code_p)/ca.code_length)
else:
n = int(fs*0.001*(2*ca.code_length-s.code_p)/ca.code_length)
x = io.get_samples_complex(fp,n)
if x is None:
break
fm = -(coffset+562500*chan)/fs
nco.mix(x,fm,coffset_phase)
coffset_phase = coffset_phase + n*fm
coffset_phase = np.mod(coffset_phase,1)
p_prompt,s = track(x,s)
print(block, np.real(p_prompt), np.imag(p_prompt), s.carrier_f, s.code_f-ca.chip_rate, (180/np.pi)*np.angle(p_prompt), s.early, s.prompt, s.late)
block = block + 1
# if (block%100)==0:
# sys.stderr.write("%d\n"%block)
if block==1000:
s.mode = 'FLL_NARROW'
if block==2000:
s.mode = 'PLL'
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 / 1540.0) / fs
p_early = l1cp.correlate(x, s.prn, 0, s.code_p - 0.2, cf,
l1cp.l1cp_code(prn), l1cp.boc11)
p_prompt = l1cp.correlate(x, s.prn, 0, s.code_p, cf, l1cp.l1cp_code(prn),
l1cp.boc11)
p_late = l1cp.correlate(x, s.prn, 0, s.code_p + 0.2, cf,
l1cp.l1cp_code(prn), l1cp.boc11)
# if s.ms>4000:
# for dci in range(320):
# dc = 0.0125*(dci-160)
# pp = l1cp.correlate(x, s.prn, 0, s.code_p+dc, cf, l1cp.l1cp_code(prn), l1cp.boc11)
# if np.real(p_prompt)>0:
# s.shape[dci] += pp
# else:
# s.shape[dci] -= pp
# s.ms = s.ms + 1
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, l1cp.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 / 118.0) / fs
p_early = b2bq.correlate(x, s.prn, 0, s.code_p - 0.5, cf,
b2bq.b2bq_code(prn))
p_prompt = b2bq.correlate(x, s.prn, 0, s.code_p, cf, b2bq.b2bq_code(prn))
p_late = b2bq.correlate(x, s.prn, 0, s.code_p + 0.5, cf,
b2bq.b2bq_code(prn))
if s.nframe > 200:
if np.real(p_prompt) > 0:
nco.accum(x, s.code_p, cf, s.chips, b2bq.code_length)
else:
nco.accum(-x, s.code_p, cf, s.chips, b2bq.code_length)
s.nframe += 1
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, b2bq.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
t = np.mod(s.carrier_p,1)
dcyc = int(round(s.carrier_p-t))
s.carrier_cyc += dcyc
s.carrier_p = t
cf = (s.code_f+s.carrier_f/1540.0)/fs
p_early = ca.correlate(x, s.prn, 0, s.code_p-0.05, cf, ca.ca_code(prn))
p_prompt = ca.correlate(x, s.prn, 0, s.code_p, cf, ca.ca_code(prn))
p_late = ca.correlate(x, s.prn, 0, s.code_p+0.05, cf, ca.ca_code(prn))
if s.mode=='FLL_WIDE':
fll_k = 3.0
a = p_prompt
b = s.prompt1
e = discriminator.fll_atan2(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_atan2(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
t = np.mod(s.code_p,ca.code_length)
dcyc = int(round(s.code_p-t))
s.code_cyc += dcyc
s.code_p = t
return p_prompt,s
