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 <<<<< N0 = Eb / (10**(EbNodB / 10)) An = pow(N0 * Fs / 2, 0.5) rt = st + An * nt # Noisy PAM signal # ***** PAM signal receiver ***** dly = 0 bn, bt, ixn = pamfun.pamrcvr10(tt, rt, [FB, dly], ptype, pparms) dnhat = array(zeros(len(bn)), int) ix = where(bn > 0)[0] dnhat[ix] = ones(len(ix)) # Received binary data, quantized # ***** Compare dn, dnhat and compute Ps(E) ***** nerror = list(abs(dn - dnhat)).count(1) PsE = nerror / len(dn)
def askrcvr(tt, rt, rtype, fcparms, FBparms, ptype, pparms):
"""
Amplitude Shift Keying (ASK) Receiver for
Coherent ('coh') and Non-coherent ('noncoh') ASK Signals
>>>>> bn,bt,wt,ixn = askrcvr(tt,rt,rtype,fcparms,FBparms,ptype,pparms) <<<<<
where bn:received DT sequence b[n]
bt:received 'CT' PAM signal b(t)
wt = wit + 1j*wqt
wit:in-phase component of b(t)
wqt:quadrature component of b(t)
ixn:sampling time indexes for b(t)->b[n], w(t)->w[n]
tt:time axis for r(t)
rt:received (noisy) ASK signal r(t)
rtype:receiver type from list ['coh','noncoh']
fcparms = [fc, thetac] for {'coh'}
fcparms = [fc] for {'noncoh'}
fc:carrier frequency in Hz
thetac:carrier phase in deg (0: cos, -90: sin)
FBparms = [FB, dly]
FB:baud rate of PAM signal, TB=1/FB
dly:sampling delay for b(t)->b[n], fraction of TB
sampling times are t=n*TB+t0 where t0=dly*TB
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'}
"""
ptype = ptype.lower()
rtype = rtype.lower()
Fs = int(len(tt) / (tt[-1] - tt[0]))
FBparms = FBparms
pparms = pparms
if rtype == 'coh':
fc = fcparms[0]
thetac = fcparms[1]
rt = 2 * rt * cos(2 * pi * fc * tt + thetac)
bn, bt, ixn = pamfun.pamrcvr10(tt, rt, FBparms, ptype, pparms)
wt = bt
bn[where(bn > 0.0001)] = 1
bn[where(bn <= 0.0001)] = 0
elif rtype == 'noncoh':
an = anthcn[0]
fc = fcparms
thetacn = anthcn[1]
vt = 2 * rt * exp(-1j * 2 * pi * fc * tt)
bni, wit, ixni, = pamfun.pamrcvr10(tt, real(vt), FBparms, ptype,
pparms)
bnq, wqt, ixnq, = pamfun.pamrcvr10(tt, imag(vt), FBparms, ptype,
pparms)
bt = (wit**2 + wqt**2)**0.5
N = ceil(FBparms[0] * (tt[-1] - tt[0]))
ixn = array(around((arange(N) + 0.5 + FBparms[1]) * Fs / FBparms[0]),
int)
bn = bt[ixn]
bn[where(bn > 0.01)] = 1
bn[where(bn <= 0.01)] = 0
wt = wit + 1j * wqt
else:
print("xtype is incorrect")
bn = array(bn, int8)
return bn, bt, wt, ixn