Recursive generation of constant amplitude multi-code DS-CDMA signal

We present a constant amplitude multi-code CDMA scheme, which achieves an information rate of (314)^K for any K, while Wada´s scheme is realizable only for 3/4 (K=1) and 9/16 (K=2). The proposed method has a recursive structure such that the input at the top-level encoder continues to be divided into three groups and lets the lower-level encoders handle the divided input. Finally, groups of three bits are separately encoded at the basic-level encoders and combined recursively to form a constant amplitude chip signal. Previous works such as Wada´s scheme and Kim´s scheme are analyzed in comparison.