Module rpps.sync.time.ed.zx

Zero-crossing TED - This requires SPS>=2 - Carrier independent

Functions

def zx_nd(early, mid, late)

Expand source code

def zx_nd(early, mid, late):
    """Gardner TED
    early, (mTm)        : near-peak sample (current symbol)
    mid,   (mTm + Tm/2) : near-zero sample
    late,  ((m+1)Tm)    : near-peak sample (next symbol)
    """
    return mid*(np.conj(early) - np.conj(late))

Gardner TED early, (mTm) : near-peak sample (current symbol) mid, (mTm + Tm/2) : near-zero sample late, ((m+1)Tm) : near-peak sample (next symbol)

Classes

class ZX_ND

Expand source code

class ZX_ND(TED_ND):
    iSPS = 2
    Inputs = 3
    Lookahead = False
    Derivative = False

    def run(self):
        """
        samples[0] = late,  ((m+1)Tm)    : near-peak sample (next symbol)
        samples[1] = mid,   (mTm + Tm/2) : near-zero sample
        samples[2] = early, (mTm)        : near-peak sample (current symbol)
        """
        r_term = (self.samples[2].real - self.samples[0].real) * self.samples[1].real
        i_term = (self.samples[2].imag - self.samples[0].imag) * self.samples[1].imag
        return r_term + i_term

Ancestors

• rpps.sync.time.ed._ed.TED_ND
• rpps.sync.time.ed._ed._TED

Class variables

var Derivative

var Inputs

var Lookahead

var iSPS

Methods

def run(self)

Expand source code

def run(self):
    """
    samples[0] = late,  ((m+1)Tm)    : near-peak sample (next symbol)
    samples[1] = mid,   (mTm + Tm/2) : near-zero sample
    samples[2] = early, (mTm)        : near-peak sample (current symbol)
    """
    r_term = (self.samples[2].real - self.samples[0].real) * self.samples[1].real
    i_term = (self.samples[2].imag - self.samples[0].imag) * self.samples[1].imag
    return r_term + i_term

samples[0] = late, ((m+1)Tm) : near-peak sample (next symbol) samples[1] = mid, (mTm + Tm/2) : near-zero sample samples[2] = early, (mTm) : near-peak sample (current symbol)