Modified SUGAR/DS: a new CDMA scheme

The authors prove by analysis the possibility of gaining a minimum of 2 dB in signal-to-noise ratio by just, splitting the users to three or more groups and identifying each one by an orthogonal waveform (on top of his short Gold code) in a PSK/DS spread-spectrum network. User signals may arrive in a code-asynchronous fashion at the receiver, however, it is shown that by using the scheme the average code cross-correlation is minimal compared to the classic code division multiple access (CDMA) system. Both the chip-synchronous and asynchronous cases are investigated and the uniform and optimal cases of dividing the users into orthogonal groups are analyzed. The superior bit error and network data throughput results in the different fading and forward error correction environments make the system a strong candidate for competitive domestic applications