Methods and systems for training sequences are provided. In one embodiment, a bi-directional communication system comprises: a multipoint-to-point host unit; and a plurality of remote units communicatively coupled to the multipoint-to-point host unit through an orthogonal frequency division multiplexing waveform. The multipoint-to-point host unit is configured to receive the orthogonal frequency division multiplexing waveform, the orthogonal frequency division multiplexing waveform comprising a plurality of tones transmitted by the plurality of remote units. The plurality of remote units each transmit a training pattern to the host unit on at least one of the plurality of tones; and the multipoint-to-point host unit is configured to adjust demodulation of upstream information from the plurality of tones based on the training pattern.