Fig. 6
From: Multichannel speaker interference reduction using frequency domain adaptive filtering
Proposed multichannel Kalman-based Wiener filter (MKWF) for interferer reduction in channel m=1. The box 
denotes the previous K − R and KWF − R samples in the buffer of the MAEC and WF, respectively; 
the elimination of K − R samples w.r.t. the OLS constraint, and 
the replacement of K − R samples by zeros. The inputs are changed accordingly to obtain \(\hat {s}_{2}(n)\) and \(\hat {s}_{3}(n)\)