摘要 |
Information is detected in a signal received from a transmission over a MIMO channel from a plurality of transmit antennas. The information is encoded as QAM symbols over space and time and/or frequency. A method of detection is provided, comprising arranging the available QAM symbols into a hierarchical tree structure, each level of the tree structure providing a greater level of granularity than the previous and, for each level of the tree structure from the least specific onwards, for each selected branch of the tree structure in said level, determining a branch likelihood measure, representing the approximated likelihood of a received signal containing a symbol in said branch, selecting one or more of said branches on the basis of their branch likelihood measures, said selected branches being selected for consideration in the next level of the tree structure, such that, at a last level, wherein each branch thereof corresponds to a symbol, said branch likelihood measure for a branch corresponds to a likelihood of said received signal containing the corresponding symbol. Corresponding detector apparatus is further provided. |