# template tile for Lab #7, Task #3
import numpy
import matplotlib.pyplot as p
import waveforms as w
import lab7

p.ion()

# transmission rate
bits_per_second = 20000

# receive amplitude-modulated transmission:
def am_receive(samples,fc,samples_per_bit,channel_bw):
    #######
    # copy your Task 2 code for am_receive to here
    # and add plot of eye diagram
    ######
    pass

if __name__ == '__main__':
    n = 8  # no. of bits of ISI to test for
    # generate all possible n-bit sequences
    message = [0] * (n * 2**n)
    for i in xrange(2**n):
        for j in xrange(n):
            message[i*n + j] = 1 if (i & (2**j)) else 0
    message = [0,0] + message + [0,0]  # periodic
    message = numpy.array(message,dtype=numpy.int)

    # send it through transmitter, modulate to legal freq near 125 kHz
    samples_per_bit = lab7.samples_per_bit(lab7.sample_rate,
                                           bits_per_second)
    fc = lab7.quantize_frequency(125e3,lab7.sample_rate,
                                 len(message)*samples_per_bit)
    xmit = lab7.am_transmit(message,samples_per_bit,lab7.sample_rate,
                            fc,lab7.channel_bw)

    # run receiver
    receive = am_receive(xmit,fc,samples_per_bit,lab7.channel_bw)

    # report results
    print 'message: ',message
    print 'received:',receive
    if not numpy.array_equal(message,receive):
        print '***** differences *****'
    else:
        print 'message received okay'