def askxmtr(anthcn, FB, Fs, ptype, pparms, xtype, fcparms):
"""
Amplitude Shift Keying (ASK) Transmitter for
Choherent ('coh') and Non-coherent ('noncoh') ASK Signals
>>>>> tt,xt,st = askxmtr(anthcn,FB,Fs,ptype,pparms,xtype,fcparms) <<<<<
where tt:time axis for x(t), starts at t=-TB/2
xt:transmitted ASK signal, sampling rate Fs
x(t) = s(t)*cos(2*pi*fc*t+(pi/180)*thetac)
tt:time axis for x(t), starts at t=-TB/2
st:baseband PAM signal s(t) for 'coh'
st = sit + 1j*sqt for 'noncoh'
sit:PAM signal of an*cos(pi/180*thetacn)
sqt:PAM signal of an*sin(pi/180*thetacn)
xtype:Transmitter type from list {'coh','noncoh'}
anthcn = [an] for {'coh'}
anthcn = [[an],[thetacn]] for {'noncoh'}
an:N-symbol DT input sequence a_n, 0<=n<N
thetacn: N-symbol DT sequence theta_c[n] in degrees,
used instead of thetac for {'noncoh'} ASK
FB:baud rate of a_n (and theta_c[n]), TB=1/FB
Fs:sampling rate of x(t), s(t)
ptype:pulse type from list ['man','rcf','rect','rrcf','sinc','tri']
pparms = [] for {'man','rect','tri'}
pparms = [k, alpha] for {'rcf','rrcf'}
pparms = [k, beta]
for {'sinc'}
k:"tail" truncation parameter for {'rcf','rrcf','sinc'}
(truncates at -k*TB and k*TB)
alpha:Rolloff parameter for {'rcf','rrcf'}, 0<=alpha<=1
beta:Kaiser window parameter for {'sinc'}
fcparms = [fc, thetac] for {'coh'}
fcparms = [fc] for {'noncoh'}
fc:carrier frequency in Hz
thetac: carrier phase in deg (0: cos, -90: sin)
"""
xtype = xtype.lower()
ptype = ptype.lower()
if xtype == 'coh':
an = anthcn
fc = fcparms[0]
tt, st = pamfun.pam12(an, FB, Fs, ptype, pparms=[])
st[where(st < 0)] = 0
thetac = fcparms[1]
xt = st * cos(2 * pi * fc * tt + thetac)
elif xtype == 'noncoh':
an = anthcn[0]
fc = fcparms
thetacn = anthcn[1]
tt, sit = pamfun.pam12(an * cos(thetacn), FB, Fs, ptype, pparms=[])
tt, sqt = pamfun.pam12(an * sin(thetacn), FB, Fs, ptype, pparms=[])
st = sit + 1j * sqt
xt = real(st * exp(1j * 2 * pi * fc * tt))
else:
print("xtype is incorrect")
return tt, xt, st
Fs = 1000 # Sampling rate
FB = 100 # Baud rate FB
EbNodB = float(EbNodB[-1]) # Specified SNR Eb/No in dB
N = 100000
# Number of symbols
ptype, pparms = 'tri', [] # Pulse type/parameters
an_set = [-1, +1] # Set of possible an values
M = len(an_set) # Number of signal levels
# ***** Compute Eb for given p(t) and signal constellation *****
Es_prime = 0
for i in an_set:
tt, pt = pamfun.pam12(array([i]), FB, Fs, ptype, pparms) # PAM signal
Es_prime += (cumsum(pt * pt) / Fs)[-1]
Es = Es_prime / len(an_set)
Eb = Es / log2(M)
# ***** Generate PAM signal using random data *****
dn = array(floor(2 * rand(N)), int) # Random binary data signal
an = 2 * dn - 1 # Polar binary sequence
tt, st = pamfun.pam12(an, FB, Fs, ptype, pparms) # PAM signal
# ***** Generate Gaussian noise signal *****
nt = randn(len(tt)) # Gaussian noise
# >>>>> Compute An such that rt has desired SNR Eb/No <<<<<