Abstract: This paper first proposes the prototype algorithm of an improved distributed power control (IDPC). In this algorithm, mobile units adjust their transmitter powers ac-cording to not only their power levels at last iterative step but also the largest and second smallest eigenvalues of the link gain matrix at current time instant. As for the prototype algorithm, link gains for all mobile units must be measured and large burden may be brought in at base stations. For this reason, the prototype algorithm is developed further in a dis-tributed way and thus lead to IDPC algorithm, in which both the positive receiver noise and constrained transmitter power are also considered. As a result, with IDPC algorithm, the CIRs are balanced quickly and a superior outage performance to other algorithms is reached.