Turbo decoding with erasures for high-speed transmission in the presence of impulse noise

If impulse noise is not taken into account, turbo codes are highly attractive for transmissions over asymmetric digital subscriber lines. We show that impulse noise could devastate turbo coding performance if appropriate precautions are not taken. A possible solution of using an outer Reed-Solomon code to combat impulse noise results in very large delays. We propose erasure turbo decoding to improve the turbo trellis coded modulation performance against impulse noise. We also show that when a concatenated coding structure is employed, in addition to improving the bit error rate performance, erasure turbo decoding can also significantly reduce the delay of the outer Reed-Solomon code.