IMPLEMENTATION OF A TIME-VARYING MIMO SYSTEM WITH ERROR FEEDBACK

The error feedback method for roundoff noise reduction is applied to a time-varying multiple-input multiple-output (MIMO) system. The optima l error feedback coefficients are derived for a general Mth-order stru cture, which reduces to M distinct optimization problems. The develope d theory is applied to a signal processor implementation of a 4th-orde r time-varying AC motor model. By employing 2nd-order error feedback. the roundoff noise can be cut down very efficiently with only 8% incre ase in program execution time, which is only a fraction of the costs o f a double-precision implementation. Although the model is time varyin g, keeping the error feedback coefficients fixed results in almost equ al reduction as with time-varying coefficients.