1. A method of adjusting transmission parameters in a multiple input multiple output based wireless communication system, wherein a base station is in communication with at least one user equipment utilizing a plurality of antenna streams, m, wherein the transmission parameters are adjusted based at least partly on reported channel quality indicators comprising information relating to at least one signal-to-interference-plus-noise ratio, and wherein a model of the signal-to-interference-plus-noise ratio dependencies of power and code allocation is utilized to adjust the transmission parameters in which the dependencies are modeled by a function comprising a first parameter relating only to power allocation with a power allocation exponent as an exponent value of the first parameter and a second parameter relating only to code allocation with code allocation exponent as an exponent value of the second parameter, the method comprising the steps of: the base station broadcasting information about reference power allocation, α ref , and code allocation, K ref ; the user equipment receiving the information about the reference power allocation, α ref , and code allocation, K ref ; the user equipment estimating for each antenna stream, m, signal-to-interference-plus-noise ratio according to the reference power allocation, α ref , and code allocation, K ref ; the user equipment estimating for each antenna stream, m, a signal-to-interference-plus-noise ratio power allocation exponent, q α (m), for the reference power allocation, α ref ; the user equipment estimating for each antenna stream, m, a signal-to-interference-plus-noise ratio code allocation exponent, q k (m), for the reference code allocation, K ref ; the user equipment reporting back to the base station the power allocation exponents, q α (m), and the code allocation exponents, q k (m); the base station adjusting the reported signal-to-interference-plus-noise ratio estimates according to instantaneous power and code allocation and the reported power allocation exponents and the code allocation exponents using the model of the signal-to-interference-plus-noise ratio dependence on the power allocation exponent and the code allocation exponent; and the base station selecting a modulation and coding scheme based on the adjusted signal-to-interference-plus-noise ratio.