US 201414197440 A description the present invention is applicable to wireless communication systems implementing ofdm and cdma such as ieee 802 11 ieee 802 16 third generation 3g cellular systems for long term evolution fourth generation 4g systems satellite systems dab digital video broadcasting dvb or the like the features of the present invention may be incorporated into an integrated circuit ic or be configured in a circuit comprising a multitude of interconnecting components the present invention provides an ofdm cdma system with an improved papr and capacity the present invention uses a special spreading code a scqs code in spreading input data symbols the scqs code comprises two components a quadratic phase sequence code and an orthogonal or pseudo orthogonal spreading code examples of the quadratic phase sequence code denoted by g are the newman phase code or polyphase code a generalized chirp like sequence gcl and a zadoff chu sequence quadratic phase sequences are called polyphase sequences as well to support a variable spreading factor vsf the sequence length of the quadratic phase sequence or polyphase sequence is limited as k 2 k in some special cases such as random access channel or uplink pilots the sequence length of quadratic phase sequence or polyphase sequence can be any arbitrary integer number given the number of subcarriers n 2 n.