A high-rate, reliable uplink transmission is designed using multistage selective maximum-likelihood (ML) decoding for the multicode (MC) direct-sequence code-division multiple access (DS-CDMA) with precoding. The precoding achieves a constant envelope MC signal by adding some redundancy bits, resulting in rate loss, but multidimensional signaling on top of MC DSCDMA enables to further increase the date rate. The designed multistage selective ML decoding is shown to be promising for use in uplink high-rate and reliable data transmission.