Decision feedback equalizer precoder

• Main Author: GAUR, SUDHANSHU
• Format: Patent
• Language: English; French; German
• Published: 09.03.2011
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

To realize a GDFE precoder for multi-user MIMO systems, which significantly reduces the computational cost while resulting in no capacity loss, one method comprises computing an effective UL channel matrix H UL using one of two methods H UL = H DL H , or H UL = [ (P t /N t ) H DL H H DL + I ] -1/2 H DL H ; extracting H k from H UL ; computing a singular value decomposition of the DL channel between the BS and k th UT, H k , for all K UTs, H k = U k S k V k H ; extracting all singular values as s =[ diag ( S 1 ),.., diag ( S k )]; extracting a vector s from s by choosing first utmost N t largest non-zero singular values of s ; sorting elements in s in decreasing order; performing water-filling to allocate power and obtain a diagonal matrix “ k representing power allocations corresponding to the singular values of the k th UT; computing an UL covariance matrix for each UT as ¦ k = U k “ k U k H ; and obtaining an overall input covariance matrix D for the equivalent UL channel.