A method, system and communication network for transmitting information signals via uplink (UL) collaborative SDMA, in a wireless communication system. Base station receiver estimates a channel gain associated with the transmission path(s) of each user and keeps a matrix of normalized covariance, between users. Based on the estimated channel gain and the normalized covariance, ULS utility is able to compute channel capacity. Based on capacity estimates of (1) the multiplexed user signals and (2) the individual user signals, signals are either multiplexed for UL SDMA or are transmitted individually. An optimal selection of multiplexed signals may be based upon: (1) a cross user interface measurement; and (2) a selection mechanism based on eigen-decomposition techniques. The ULS utility enables a UL scheduler to pair information signals with clear spatial distinction and minimal correlation, based on capacity evaluations.