1. A method of adjusting transmission parameters in a multiple input multiple output, hereinafter referred to as MIMO, based wireless communication system, wherein a base station is in communication with at least one user equipment utilizing a plurality of antenna streams, m, the adjustment based at least partly on reported channel quality indicators, hereinafter referred to as CQI, wherein the CQI comprises information relating to at least one signal-to-interference-plus-noise ratio, hereinafter referred to as SINR, and in that the adjustment of transmission parameters for use in transmissions from the base station, a model of the SINR dependences of power and code allocation is utilized wherein the dependences is modeled by a function comprising a first parameter relating only to power allocation with a power allocation exponent, and a second parameter relating only to code allocation with a code allocation exponent.