def METHOD_NAME(self, L):
    # Filter delay is the normal delay of each arm
    tpf = math.ceil(len(self.taps) / float(self.M))
    delay = -(tpf - 1.0) / 2.0
    delay = int(delay)
    # Create a time scale that's delayed to match the filter delay
    t = [float(x) / self.fs for x in range(delay, L + delay)]
    # Create known data as complex sinusoids at the different baseband freqs
    # the different channel numbering is due to channelizer output order.
    expected_data = [[math.cos(2. *
                               math.pi *
                               f *
                               x) +
                      1j *
                      math.sin(2. *
                               math.pi *
                               f *
                               x) for x in t] for f in self.freqs]
    return expected_data