Signaling MIMO allocations
View Patent ↗The present invention relates to demodulation of radio signals from a base station having collocated transmit antennas, and more particularly to signaling allocation information from a base station to a mobile terminal. The allocation information may include timeslot and code information of allocation to other mobile terminals. Some embodiments of the present invention facilitate a mobile terminal's ability to receive and demodulate a signal containing multiple interfering signals by communicating codes allocated to other mobile terminals.
1. A method of communicating code allocations by a base station in a Multiple Input Multiple Output (MIMO) cellular radio system, the base station comprising a plurality of antennas, the method comprising:
determining, by the base station, a first set of codes in a timeslot to allocate to a first mobile terminal for communication with the base station, the allocation including an allocation of an antenna of the plurality to each code of the first set;
determining, by the base station, a second set of codes in the timeslot to allocate to a second mobile terminal for communication with the base station, the allocation including an allocation of an antenna of the plurality to each code of the second set;
generating an allocation table, by the base station, describing the allocation of the first set of codes and the second set of codes, including the respective antenna allocations; and
transmitting the allocation table, wherein transmitting the allocation table includes transmitting the allocation table during a period prior to the timeslot.
2. The method of claim 1 , wherein transmitting the allocation table includes transmitting the allocation table after a change is made to the allocation table.
3. The method of claim 1 , wherein transmitting the allocation table includes transmitting the allocation periodically.
4. The method of claim 1 , wherein transmitting the allocation table includes transmitting the allocation once per frame.
5. The method of claim 1 , wherein transmitting the allocation table includes:
encoding the allocation table with an error correcting code; and
transmitting the encoded allocation table.
6. The method of claim 1 , wherein transmitting the allocation table includes transmitting the allocation once per MIMO timeslot in a frame.
7. The method of claim 6 , wherein the timeslot is a MIMO timeslot, and transmitting the allocation table once per MIMO timeslot includes:
encoding the allocation table; and
transmitting the encoded allocation table during a period in which a training sequence is transmitted.
8. The method of claim 1 , wherein the allocation table includes a bit map.
9. The method of claim 8 , wherein the bit map indicates which codes of which timeslots are allocated in a frame.
10. The method of claim 1 , wherein the act of transmitting the allocation table includes:
determining a transmit power level that allows all mobile terminals having one or more allocated codes in the timeslot to receive the message, wherein the power level is less than a maximum transmitter power level; and
transmitting the allocation table at the determined power level.
11. The method of claim 1 , wherein the act of transmitting the allocation table includes:
determining a transmit power level that allows at least one mobile terminals having one or more allocated codes in the timeslot to receive the message, wherein the power level is less than a maximum transmitter power level; and
transmitting the allocation table at the determined power level.