COMMUNICATION DEVICES AND METHODS FOR SIGNAL DETECTION

• US 20140211831A1
• Filed: 01/28/2013
• Published: 07/31/2014
• Est. Priority Date: 01/28/2013
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Mobile Communications GmbH (Intel Corporation)
• Inventors: Xu, Wen, Bauch, Gerhard, Zhou, Guangxia
• Granted Patent: US 9,066,247 B2
• Time in Patent Office: Days
• US Class Current: 375/219
• CPC Class Codes: H04L 1/0656 Cyclotomic systems, e.g. Bell Labs Layered Space-Time [BLAST]
• CPC Class Codes: H04L 25/03891 Spatial equalizers MIMO diversity systems H04B7/0413
• CPC Class Codes: H04L 27/0012 arrangements for identifying the type of modulation
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition

Abstract

A communication device is described comprising a receiver configured to receive a receive symbol vector resulting from a transmission of a transmit symbol vector from at least one transmitter to the receiver wherein the transmit symbol vector comprises a plurality of transmit symbols wherein each transmit symbol is associated with a modulation type and a detector configured to determine a detection order for the plurality of transmit symbols based on the modulation types and to determine, for at least one bit of at least one transmit symbol, at least one soft value based on the receive symbol vector according to the detection order.

Claims

1. A communication device comprising

a receiver configured to receive a receive symbol vector resulting from a transmission of a transmit symbol vector from at least one transmitter to the receiver wherein the transmit symbol vector comprises a plurality of transmit symbols wherein each transmit symbol is associated with a modulation type;

and

a detector configured to determine a detection order for the plurality of transmit symbols based on the modulation types and to determine, for at least one bit of at least one transmit symbol, at least one soft value based on the receive symbol vector according to the detection order.

2. Communication device according to claim 1, wherein the detector is configured to determine, for at least one bit of at least one transmit modulation symbol, a soft value for at least one bit associated with the transmit modulation symbol.

3. Communication device according to claim 2, wherein the soft value for the bit associated with the transmit modulation symbol specifies a likelihood of the bit having a predetermined value.

4. Communication device according to claim 1, wherein the detector is configured to determine the detection order by bit error probability.

5. Communication device according to claim 4, wherein the detector is configured to determine the bit error probability by a look-up table.

6. Communication device according to claim 1, wherein the detector is configured to determine the soft value according to the detection order by performing a tree search according to the detection order.

7. Communication device according to claim 6, wherein performing the tree search according to the detection order comprises determining candidate modulation symbols for the transmit symbols in the order as given by the detection order.

8. Communication device according to claim 1, wherein the modulation type is the modulation order.

9. Communication device according to claim 1, wherein the receiver is further configured to receive modulation information specifying which modulation types are associated with the transmit symbols.

10. Communication device according to claim 1, wherein the receive symbol vector results from a transmission of the transmission symbols by means of a plurality of transmit signals.

11. Communication device according to claim 10, wherein the plurality of transmit signals are transmit signals transmitted from a plurality of different transmitters.

12. Communication device according to claim 1, wherein the receive symbol vector results from a transmission of a first set of transmission symbols transmitted by a first transmitter and a second set of transmission symbols transmitted by a second transmitter, wherein the first set of transmission symbols is associated with a first modulation type and the second set of transmission symbols is associated with a second modulation type.

13. Communication device according to claim 12, wherein the first transmitter is a first base station and the second transmitter is a second base station.

14. Communication device according to claim 12, wherein the first transmitter is a first communication terminal and the second transmitter is a second communication terminal.

15. Communication device according to claim 1, wherein the communication device comprises a plurality of receive antennas, the receiver is configured to receive the receive symbol vector by means of the receive antennas and the receive symbol vector comprises a receive symbol for each receive antenna received by means of the receive antenna.

16. Communication device according to claim 1, wherein the detector is further configured to determine the bits associated with the transmit symbol based on the soft value.

17. A method for signal detection comprising

receiving a receive symbol vector resulting from a transmission of a transmit symbol vector from at least one transmitter to the receiver wherein the transmit symbol vector comprises a plurality of transmit symbols wherein each transmit symbol is associated with a modulation type;

determining a detection order for the plurality of transmit symbols based on the modulation types; and

determining, for at least one bit of at least one transmit symbol, at least one soft value based on the receive symbol vector according to the detection order.

18. The method according to claim 17, further comprising

determining the bits associated with the transmit symbol based on the soft value.

19. A communication device comprising

a receiver configured to receive a receive symbol vector resulting from a transmission of a transmit symbol vector from at least one transmitter to the receiver wherein the transmit symbol vector comprises a plurality of transmit symbols;

a first detector configured to determine, for at least one bit of a transmit symbol, a first soft value;

a second detector, configured to determine, based on the first soft value, a tree pruning criterion and determine, for at least one bit of a transmit symbol, a second soft value using a tree search based on the tree pruning criterion.

20. Communication device according to claim 19, wherein the first detector is a linear MMSE detector.

21. Communication device according to claim 19, wherein determining the tree pruning criterion includes determining a threshold and wherein the tree pruning criterion includes excluding all tree nodes having a metric above the threshold from the tree search.

22. Communication device according to claim 21, wherein the second detector is configured to determine the threshold as the sum of a metric of an estimate of the transmit symbols and a predetermined value.

23. Communication device according to claim 22, wherein the first detector is configured to determine, for each transmit symbol, for at least one bit of the transmit symbol, a first soft value and wherein the second detector is configured to determine the metric of an estimate of the transmit symbols based on the first soft values.

24. Communication device according to claim 19, wherein the second detector is further configured to determine the bits associated with the transmit symbol based on the second soft value.

25. A method for signal detection comprising

receiving a receive symbol vector resulting from a transmission of a transmit symbol vector from at least one transmitter to the receiver wherein the transmit symbol vector comprises a plurality of transmit symbols;

determining, for at least one bit of a transmit symbol, a first soft value;

determining, based on the first soft value, a tree pruning criterion and determining, for at least one bit of a transmit symbol, a second soft value using a tree search based on the tree pruning criterion.

26. The method according to claim 25, further comprising determining the transmit symbol based on the second soft value.