US 7,680,026 B2Granted

Method and apparatus for improving reception in wireless networks subjected to neighboring cells' interferences

AssigneeAlvarion Ltd.

InventorDan Stopler

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Abstract

A method is provided for estimating a signal received at a wireless cell along a channel where the frequency used for conveying traffic is substantially equal to frequency used for conveying traffic along at least one other channel extending from/to at least one substantially interfering cell. The method comprises: associating a pilot sequence with operative cells; providing a receiver with information to allow estimation of the pilot sequence by a respective transmitter; providing the receiver with information to allow estimation of pilot sequences associated with other transmitters communicating with other receivers located at the geographical proximity of that receiver; estimating the signal associated with the pilot sequence used by the first transmitter; subtracting the estimated signal from an input signal received by that receiver; estimating the pilot signal associated with a pilot sequence used by other transmitters; and modifying the estimation of the pilot signal used by the first transmitter.

Claims9

Dependent claims

A method for use in a wireless network comprising a plurality of wireless communication cells and a plurality of communication channels extending therebetween, for estimating a signal received at a first wireless communication cell selected from among said plurality of wireless communication cells after being transmitted along a first communication channel, wherein transmission/reception frequency used for conveying traffic along said first communication channel is substantially equal to transmission/reception frequency used for conveying traffic along at least one other communication channel extending from/to at least one considerably interfering cell, which method comprising:

associating a pilot sequence with each one of the plurality of wireless communication cells;
(ii) providing at least one receiver with information related to the operation of a first transmitter with which the at least one receiver communicates and wherein that information comprises information that would allow estimation of the pilot sequence used by that first transmitter;
(iii) providing that at least one receiver with information related to the operation of other transmitters that are operative to communicate with one or more receivers located at the geographical proximity of that at least one receiver, which information comprises information that would allow estimation of the pilot sequences associated with these other transmitters;
(iv) estimating the signal associated with the pilot sequence used by the first transmitter;
(v) subtracting the estimated signal from an input signal received by that at least one receiver
(vi) estimating the pilot signal associated with a pilot sequence used by at least one of the other transmitters based on the difference obtained in step (v);
and
(vii) carrying out a modified estimation of the pilot signal used by the first transmitter, based on canceling the estimated result of step (vi) from the input of step (iv) and multiplying the resulting difference by the pilot sequence associated with the first transmitter.

5 more elements

A wireless receiver for receiving communications conveyed along at least one communication channel extending in a wireless network which comprises a plurality of wireless communication cells and a plurality of communication channels extending therebetween, wherein the transmission/reception range of frequencies used for conveying traffic along that at least one channel is substantially the same range of transmission/reception frequencies used for conveying traffic along at least one other communication channel extending from/to at least one considerably interfering cell, wherein said receiver comprising:

an interface operative to receive wireless communications along said at least one communication channel and at least one pre-defined pilot sequence of signals associated with that at least one communication channel;
at least one processing means comprising:
a database for storing
(a) information related to the operation of at least one transmitter operative to transmit communications towards the receiver along that at least one channel, wherein that information comprises information that would allow reconstruction of the at least one pre- defined pilot sequence of signals associated with the at least one channel;
and/or
(b) information related to the operation of other transmitters that are operative to communicate with one or more other receivers which would allow reconstruction of the pilot sequences used by these other transmitters;
and
a processor for:
(1) retrieving that at least one pre-defined pilot sequence of signals associated with that at least one communication channel and comprised in communication transmissions received;
(2) carrying out an estimation of that at least one pre-defined pilot sequence of signals;
(3) Carrying out an estimation of a signal associated with at least one other pilot sequence;
(4) modifying said estimation of the at least one pre-defined pilot sequence used by said first transmitter, based on canceling the estimated result of the signal associated with said at least one other pilot sequence from the estimated result carried of said at least one pre-defined pilot sequence of signals;
and
(5) applying the resulting modified estimation to pilot signals received along the corresponding at least one communication channel to obtain an updated modified estimation of said pilot signals.

11 more elements

A mobile wireless receiver for receiving communications conveyed along at least one communication channel extending in a wireless network which comprises a plurality of wireless communication cells and a plurality of communication channels extending therebetween, wherein the transmission/reception range of frequencies used for conveying traffic along that at least one channel is substantially the same range of transmission/reception frequencies used for conveying traffic along at least one other communication channel extending from/to at least one considerably interfering cell, wherein said receiver comprising:

an interface operative to receive wireless communications along said at least one communication channel and at least one pre-defined pilot sequence of signals associated with that at least one communication channel;
at least one processor for:
(1) retrieving information related to the operation of at least two different transmitters operative to transmit communications to a location in which said mobile wireless receiver is currently located, wherein that information comprises information that would allow reconstruction of the at least one pre-defined pilot sequence of signals associated with said at least one channel;
(2) carrying out an estimation of that at least one pre-defined pilot sequence of signals;
(3) carrying out an estimation of a signal associated with the other pilot sequences;
(4) modifying said estimation of the at least one pre-defined pilot sequence used by one of said at least two transmitters, based on canceling the estimated result of the signals associated with each of the other pilot sequence from the estimated result carried of that at least one pre-defined pilot sequence of signals;
and (5) applying the resulting modified estimation to the pilot signals received along the corresponding at least one communication channel to obtain an updated modified estimation of pilot signals received along that at least one communication channel.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/475,245Filed 27 Jun 2006
Priority: IL 16941727 Jun 2005
Published: US 2007/0008873 A111 Jan 2007
Granted: 16 Mar 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H04L 27/2647
Multicarrier modulation systems: arrangements specific to the receiver only
H04B 1/7107
The interference being multiple access interference: subtractive interference cancellation
H04L 25/0204
Channel estimation: of multiple channels
H04L 27/261
Signal structure: details of reference signals