==== EP1492241-B1 ==== * DE60311782(T2).pdf * EP1492241(A1).pdf * EP1492241(B1).pdf * US20050008091(A1).pdf Improved sphere decoding of symbols transmitted in a telecommunication system Joseph Boutros, Nicolas Gresset, Loic Brunel The authors proposed to use a sphere decoder algorithm feeded by a posteriori probabilities to demodulate MIMO signals. The patent focus on an efficient STBC decoding apparatus which requires less computing power than the known techniques and ensures, by directly centering the sphere on a symbol belonging to the lattice constellation instead of centering it on a point representing the received symbol, that said sphere will indeed encompass a statistically significant number of lattice constellation symbols. ==== DE102004013866-B4 ==== * DE102004013866(A1).pdf * DE102004013866(B4).pdf Digital point to multi-point transmission interference reduction signal processing procedure uses shaping vector selected to minimize Euclidean norm of difference vector Holger Boche, Martin Schubert, Shuying Shi ==== EP1521375-A2 ==== * EP1521375(A2,A3).pdf * GB2406760(A).pdf * GB2418816(A).pdf * US20050111592(A1).pdf * WO2005034360(A1).pdf Signal decoding methods and apparatus Mong Suan Yee The patent describes a soft-in soft-out decoder comprising several hard decoders (sphere decoders) each configured to determine the MAP metric coupled to an output stage to provide a bit likelihood value for each bit. In GB2418816A, all MAP likelihood detectors share distance metric information ==== EP1521414-A1 ==== * EP1521414(A1).pdf * GB2406761(A).pdf * US20050094742(A1).pdf * WO2005034455(A1).pdf Method and apparatus for sphere decoding Mong Suan Yee The patent describes a reduce complexity implementation of a sphere decoding algorithm for STBC and STTC MIMO signals. The search radius is bounded by the received signal and the number of candidate symbol tests is also limited. ==== EP1545039-B1 ==== * EP1545039(A1).pdf * EP1545039(B1).pdf Method for interpreting transmitted symbols involving a list sphere radius tuning step Loic Brunel, Nicolas Gresset, Joseph Boutros The authors have observed that, in certain circumstances during the search phase of a sphere decoder, all listed symbols produced by the symbol listing step are such that at least one of the bits representing the listed symbols is invariant from any one listed symbol to another. So, they propose to set the corresponding bit probability to 1 or 0 and the patent describes a way to do it. ==== EP1545082-A3 ==== * EP1545082(A2,A3).pdf * WO2005060191(A2,A3).pdf * GB2409386(A).pdf * US20050135498(A1).pdf Signal decoding methods and apparatus Mong Suan Yee The patent describes a reduce complexity implementation of a sphere decoding algorithm for non-square modulations. ==== EP1677437-A3 ==== * EP1677437(A2,A3).pdf * US20060146965(A1).pdf Apparatus and method for detecting a signal in a multiple-input multiple-output mobile communication system Kwun Jong-Hyung, Hwang Chan-Soo, Lee Kyung-Chun, Chun Joo-Hwan The patent proposes a method for detecting a STBC signal using sphere decoding in which detection starts with lattice points near to a Babai point and the sphere radius limiting the search is updated an initial MDDF method. ==== FR2901434-A1 ==== * FR2901434(A1).pdf * WO2007132084(A1).pdf Procede de decodage de codes spatio-temporels 2x2, notamment de type golden code David Champion The author proposes an apparatus to decode STBC signal especially those named Golden codes. After a MMSE-GDFE filtering, the received vector is realigned to get a lattice base reduction. Then a ZF-DFE algorithm process layer by layer to finally decode the signal. ==== GB2426419-A ==== * GB2426419(A).pdf A hardware accelerator for a signal decoder David Milford The author describes an hardware accelerator for sphere decoding implementation. It focus on a most likely symbol candidate to start a constrained search and therefore determine bit likelihood value for each bit. ==== GB2426419-A ==== * GB2427106(A).pdf Sphere decoder for MIMO applications with reduced computational complexity decomposition of the channel estimate matrix Sebastien Nicolas Scarwell Instead of doing a QR decomposition of the channel matrix, the author proposes to decompose it into the product of three matrices: the right product matrix is an upper triangular matrix ($P$) with diagonal elements all equal to 1, the central one is a diagonal matrix ($D$) and the left one ($T$) is such as $\det(T) = \det(H)^{-1}$ and $T^\herm T = D^{-1}$. This transformation is less complex and provides same performance as the QR decomposition. ==== WO2006029546-A3 ==== * WO2006029546(A2,A3).pdf Method and device for decoding signal of a multiple input/multiple output system Andreas Burg, Moritz Borgmann, Markus Wenk, Martin Zellweger The authors describe a certain implementation of the sphere decoder based on two separate hardware unit, namely an MCU and a MEU which could operate simultaneously. The MCU determines a next child node which the MEU determines next best parent nodes. ==== WO2006135141-A1 ==== * WO2006135141(A1).pdf Soft output sphere decoding method Jong-ee Oh, Dong-seung Kwon The patent provides a soft output sphere decoding method enhancing the standard hard decision sphere decoder by calculating a ratio between a distance from the receiving signal to the detected maximum likelihood symbol and a distance from the receiving signal to the calculated lattice points for each bit.