Cochannel interference (CCI) and InterSymbol Interference (ISI), are two main impairments that affect the performance of a wireless system. In this article the Duality Principle widely known is used to propose a Multiuser system with antenna arrays and equalization at both ends of the wireless link. For this system a Joint Multitap Transmit-Receive and Power Control algorithm for a channel with ISI, is obtained as an extended version of a previous proposal made for a joint single tap transmit-receive and power control algorithm for channels with no ISI, with the objective to Minimize the sum of the Total Transmitted Power while keeping the Signal to Interference plus Noise Ratio (SINR) above a target at all links. Channel estimation is also included, in order to study its impact on the performance of the system and have more realistic approximations of its behavior. Simulations were performed in order to obtain numerical results in terms of Interference Probability.