Method and modem for generating multi-carrier training sequences based on its cyclic time-domain shift with respect to a reference sequence

摘要

A method and apparatus for generating specific multi-carrier time domain sequences with and without extension (1020;1030) using existing sequence generation hardware without requiring the storage of the entire sequence is presented. A cyclic shift between a time domain reference sequence and the desired sequence is calculated. Depending on said cyclic shift (S), an equivalent frequency domain rotation vector is calculated (1040) using the expression: 360*S/N*M, N being the length of the desired sequence and M being a multiple of fundamental frequency used for each frequency domain constellation during modulation. Instead of storing the entire sequence, the method requires only the storage of a reference sequence and a series of rotation vectors. <IMAGE>