Model of complication function for generator of pseudorandom sequences over the field $\mathrm{GF}(2)$

A complication model for pseudorandom sequences (PRS) over $\mathrm{GF}(2)$ is proposed. The complication function in the model is represented by the system of linear bijective transformations of bit pairs being next in turn in the sequence. Transformations in the system can vary from time to time making possible to generate a great ensemble of complicated PRS.