Method for improving coexistence between adjacent TDD and FDD wireless networks

• US 7,929,468 B2
• Filed: 07/01/2009
• Issued: 04/19/2011
• Est. Priority Date: 04/07/2008
• Status: Expired due to Fees

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Alvarion Limited
• Inventors: Goldhamer, Mariana
• Primary Examiner(s): Yao; Kwang B
• Assistant Examiner(s): Elpenord; Candal
• Application Number:
  US12/495,975
• Publication Number:
  US 20100002608A1
• Time in Patent Office: 657 Days
• Field of Search: 370/280, 370229-330, 370342-343, 370/328, 370/344, 370/281, 375/346, 455/452.1, 455/63.2, 455/63.3
• US Class Current: 370/280
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow

Abstract

A method for reducing interference between FDD and a TDD interfering radio networks including identifying respective radio entities for which the interferences should be reduced; defining a time pattern comprising time slots on each of the interfered channels, and receive time intervals for radio entities that may be interfered, and aligning the time patterns so that receive time intervals for the radio entities that are potentially exposed to interferences, overlap each other. The radio entity that might create interference to the radio entity of the pre-defined type of the other network, is prevented from transmitting communications that might create e substantial interference to the radio entity associated with the other radio network, and communications transmitted to some radio entities of the pre-defined types that might experience interference, are scheduled at intervals in which communications are received with substantially reduced interference.

Claims

1. A method for reducing interference between at least two interfering radio networks, each comprising a plurality of radio entities, wherein at least one of the radio networks is operative in frequency division duplex (FDD) mode and at least one of the other radio networks is operative in a time division duplex (TDD) mode, said method comprising:

for each of said at least of the radio networks operative in the FDD mode and said at least one of the radio networks operative in the TDD mode, identifying respective the radio entities for which interferences should be reduced, and wherein for each of the at least two networks, the respective radio entities are of a pre-defined type;

defining a time pattern composed of time slots on each of the interfered FDD and TDD frequency channels, said time pattern comprising receive time intervals for the respective radio entities of the pre-defined types that are likely to be interfered while receiving communications transmitted thereto;

aligning said defined time patterns for each of FDD frequency channel and a TDD frequency channel interfering therewith so that said receive time intervals for at least two of the respective radio entities of the pre-defined types that are potentially exposed to interferences, overlap each other;

defining at least two types of time intervals within said time pattern on each of the FDD and TDD frequency channels, wherein a first type of time intervals is adapted to enable at least one of the radio entities to receive communications with substantially reduced interference and wherein a second type of time intervals is adapted for exchanging communications without mitigating interferences induced by at least one other of the radio entities transmitting during said time intervals, wherein at least one radio entity that might create interference to at least one of the radio entities of the pre-defined type associated with the at least one other radio network, is prevented from transmitting any communications that might create substantial interference to said at least one radio entity associated with the at least one other radio network, and wherein communications transmitted to at least some of the radio entities of the pre-defined types that might experience interference from others of the radio entities of the at least one other network are scheduled at intervals of the first type.

2. A method according to claim 1, wherein the duration of at least one time interval of the first type of the time pattern and the duration of at least one time interval of the second type of that time pattern, are dynamically modified.

3. A method according to claim 2, wherein the dynamic modification is carried out to comply with current traffic loads.

4. A method according to claim 1, wherein the alignment of a time pattern associated with an FDD radio network, with the time pattern of a TDD radio network, is achieved by shifting the time pattern of one of said time patterns in order to synchronize it with a time pattern of the other one of the two radio networks.

5. A method according to claim 1, wherein low power transmissions are allowed to be transmitted by the radio network potentially creating interference during at least one interval of the first type within the time pattern.

6. A method according to claim 1, wherein at least one of the radio entities of the pre-defined type that would receive communications during said intervals of the first type, are radio entities that are potentially exposed to higher interferences than other radio entities of the same pre-defined type associated with the same radio network.