Method of selecting a receiving path and receiving device comprising sereral receiving paths

• US 20050063496A1
• Filed: 11/20/2002
• Published: 03/24/2005
• Est. Priority Date: 12/06/2001
• Status: Active Grant

• Current Assignee: Magnolia Licensing LLC (IP Edge LLC)
• Original Assignee: Thomson Licensing SA (Vantiva SA)
• Inventors: Demoulin, Vincent, Lopez, Patrick, Fontaine, Patrick, Guillouard, Samuel
• Granted Patent: US 7,558,347 B2
• Time in Patent Office: Days
• US Class Current: 375/346
• CPC Class Codes: H04B 7/0811 during preamble or gap period
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01

Abstract

The invention provides a method of evaluating a path in a data-receiving system using multi-carrier modulation. A confidence indicator is determined for each data item received so as to provide a stream of confidence indicators parallel to the datastream received. The confidence indicators are ordered identical to the data received. The invention provides a device comprising means for evaluating a confidence indicator for each carrier and means for laying out a stream of confidence indicators identical to a datastream received.

Claims

1. Method of selecting a receiving path for a device comprising at least two receiving paths in order to receive a signal modulated simultaneously over a plurality of carriers, each carrier transporting a sequence of symbols, all the symbols transmitted simultaneously over all the carriers forming a series of symbols, a separate evaluation of the receiving paths being carried out for at least one evaluation period, wherein, for each receiving path and for the evaluation period:

a confidence indicator is determined for the signal corresponding to each carrier and to each symbol received,

the symbols received are then transformed into a bitstream to which a stream of confidence indicators is allocated, each confidence indicator being allocated to a bit of a received symbol, the stream of confidence indicators being ordered identical to the bitstream.

2. Method according to claim 1, wherein the confidence indicators correspond to power measurements for the carriers carried out during the demodulation of the carriers.

3. Method according to claim 2, wherein sliding averages are produced over a small number of confidence indicators, the small number being less than the total number of bits which can be transmitted simultaneously over the plurality of carriers, and in that the sliding averages serve to determine which is the best receiving path.

4. Method according to claim 3, wherein a criterion for evaluating a path corresponds to the minimum sliding average obtained for a path in the evaluation period.

5. Method according to claim 4, wherein the path chosen corresponds to the highest minimum sliding average.

6. Method according to claim 3, wherein, for each path:

the mean power for receiving the signal is measured during the evaluation time,

the minimum sliding average is determined during the evaluation time,

the mean receiving power is combined with the minimum sliding average,

and in that the path is chosen as a function of the combination of the mean power with the minimum sliding average.

7. Method according to claim 1, wherein the evaluation period corresponds to an evaluation burst and starts for one path after at least one symbol has been received on each carrier.

8. Device for receiving a signal modulated over a plurality of carriers, each carrier transporting a sequence of symbols, all the symbols received simultaneously on the plurality of carriers forming a series of symbols, the device comprising:

at least two receiving paths

demodulation means for demodulating the symbols received by the various carriers,

transcoding means for transforming the series of symbols received into a bitstream received, wherein it further comprises;

at least one means for determining a confidence indicator associated with each symbol for each carrier during the demodulation,

at least one layout means for transforming the confidence indicators determined for each carrier into a stream of confidence indicators ordered identical to the bitstream, such that each confidence indicator is associated with a bit.

9. Device according to claim 8, wherein the confidence indicator is a measurement of the carrier power, and in that the device comprises means for carrying out sliding averages on the confidence indicators.

10. Device according to claim 9, wherein it comprises a means for determining the minimum value of the sliding averages carried out during the evaluation period.