Method and apparatus for sector channelization and polarization for reduced interference in wireless networks

• US 20040259563A1
• Filed: 06/01/2004
• Published: 12/23/2004
• Est. Priority Date: 11/21/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Bandspeed, Inc. (Broadcom, Inc.)
• Inventors: Skafidas, Efstratios, Jones, Ben, Morton, John Jack
• Granted Patent: US 7,512,404 B2
• Time in Patent Office: Days
• US Class Current: 455/452.2
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H04B 7/0491 using two or more sectors, i.e. sector diversity
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

The present invention provides in one embodiment channel allocation and polarization techniques for reducing cross sector communications interference in a multiple access wireless communications environment. In one embodiment, channel allocation and/or polarization techniques may be applied in multiple-access wireless communications architectures to provide selective, simultaneous communications with wireless devices using a plurality of transmitters. In some embodiments, a transmitter is coupled to an antenna configured to provide simultaneous communications with wireless devices located in different spatial areas or sectors. In some embodiments, communications between wireless devices within a single sector, between wireless devices in different sectors and between wireless devices and a wired network or wireless backhaul network may be provided.

Claims

1. A method for determining an assignment of wireless communications channels to a plurality of wireless communications transmitters, comprising:

determining a plurality of available wireless communications channels;

determining a plurality of wireless communications channel assignments based upon the plurality of available wireless communications channels and a number of wireless communications transmitters in the plurality of wireless transmitters; and

selecting from the plurality of wireless communications channel assignments, a particular wireless communications channel assignment that provides less interference relative to other wireless communications channel assignments in the plurality of wireless communications channel assignments.

2. The method as recited in claim 1, wherein:

the method further comprises determining a power for each wireless communications channel assignment in the plurality of wireless communications channel assignments; and

the step of selecting from the plurality of wireless communications channel assignments, a particular wireless communications channel assignment that provides less interference relative to other wireless communications channel assignments in the plurality of wireless communications channel assignments includes;

selecting from the plurality of wireless communications channel assignments, a particular wireless communications channel assignment that provides less interference relative to other wireless communications channel assignments in the plurality of wireless communications channel assignments and satisfies a power criteria.

3. The method as recited in claim 2, wherein determining a power for each of the wireless communications channel assignments, further comprises:

determining

$P<br><br>\left(S_j\right)=\underset{\underset{\underset{i\ne <br><br>k}{k=1<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>n}}{i=1<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>n}}{\min }<br><br>\left|S_j^i-S_j^k\right|;<br><br>$

wherein Sⁱ_j denotes an ith element of a set S_j,

which is a jth subset of Ψ

, wherein Ψ

={C₁, . . . , C_m} denotes a set of m available channels in a band of interest.

4. The method as recited in claim 1, wherein:

the method further comprises;

determining a channel separation for each of the plurality of wireless communications channel assignments;

the step of selecting from the plurality of wireless communications channel assignments, a particular wireless communications channel assignment that provides less interference relative to other wireless communications channel assignments in the plurality of wireless communications channel assignments includes;

selecting from the plurality of wireless communications channel assignments, a particular wireless communications channel assignment that provides less interference relative to other wireless communications channel assignments in the plurality of wireless communications channel assignments and satisfies a channel separation criteria.

5. The method as recited in claim 4, wherein the step of determining a channel separation for each of the plurality of wireless communications channel assignments includes:

determining

$S<br><br>\left({\stackrel{\_}{S}}_{k,i}\right)=\underset{r=1<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>n}{\min }<br><br>\left|{\stackrel{\_}{S}}_{k,i}^r-{\stackrel{\_}{S}}_{k,i}^{r+1<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{mod}<br><br>\text{\hspace{1em}<br><br>}<br><br>n}\right|$

wherein {overscore (S)}_k,i defines a wireless communications channel assignment i for a channel set S_k, comprising particular ones selected from the plurality of available communications channels, and wherein {overscore (S)}_k,i corresponds to an ordered set of elements of the channel set S_k;

wherein a first element corresponds to a first wireless communications transmitter of the wireless communications channel assignment i and an nth element corresponds to an nth wireless communications transmitter of the wireless communications channel assignment i.

6. The method as recited in claim 4, wherein the step of determining a channel separation for each of the plurality of wireless communications channel assignments includes:

determining

$S<br><br>\left({\stackrel{\_}{S}}_{k,i}\right)=\underset{r=1,\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>},n}{\min }<br><br>\left|{\stackrel{\_}{S}}_{k,i}^r-{\stackrel{\_}{S}}_{k,i}^{r+1}\right|$

wherein {overscore (S)}_k,i defines a wireless communications channel assignment i for a channel set S_k, comprising particular ones selected from the plurality of available communications channels, and wherein {overscore (S)}_k,i corresponds to an ordered set of elements of the channel set S_k;

wherein a first element corresponds to a first wireless communications transmitter of the wireless communications channel assignment i and an nth element corresponds to an nth wireless communications transmitter of the wireless communications channel assignment i.

7. The method as recited in claim 1, wherein wireless communications channels are selected from a frequency band specified by one of the IEEE 802.11(a), (b), (g), the 802.15(x), 802.16(x) and 802.20(x) wireless communications standards.

8. The method as recited in claim 1, wherein selecting from the plurality of wireless communications channel assignments, a particular wireless communications channel assignment that provides less interference relative to other wireless communications channel assignments in the plurality of wireless communications channel assignments includes:

determining an interference cost.

9. The method as recited in claim 8, wherein determining an interference cost includes using one of:

10. The method as recited in claim 9, wherein the interference function further comprises:

11. A method for determining an assignment of wireless communications channels to a plurality of wireless communications transmitters, comprising:

determining available wireless communications channels by;

selecting a first plurality of sets of wireless communications channels from a band of wireless communications frequencies;

determining a power for each set of the first plurality of sets of wireless communications channels;

ordering the first plurality of sets of wireless communications channels by power to form an ordered plurality of sets of wireless communications channels; and

selecting from the ordered plurality of sets of wireless communications channels, sets of wireless communications channels that satisfy power criteria to form a second plurality of sets of wireless communications channels;

determining channel to transmitter assignments by;

for each set of the second plurality of sets of wireless communications channels, determining each possible assignment of channels in the set to transmitters;

for each possible assignment of channels in the set to transmitters, determining a separation between the channels;

for each possible assignment of channels in the set to transmitters, determining whether the separation satisfies a specified separation criteria; and

adding possible assignment of channels in the set to transmitters to a plurality of candidate channel to transmitter assignments, if the possible assignment of channels in the set to transmitters satisfies the specified separation criteria; and

selecting a channel to transmitter assignment by;

determining an overall interference generated by each one of the plurality of candidate channel to transmitter assignments; and

choosing a candidate channel to transmitter assignment that reduces the overall interference.

12. An apparatus, comprising:

means for determining a plurality of available wireless communications channels;

means for determining a plurality of wireless communications channel assignments based upon the plurality of available wireless communications channels and a number of wireless communications transmitters in a plurality of wireless transmitters; and

means for selecting from the plurality of wireless communications channel assignments, a particular wireless communications channel assignment that provides less interference relative to other wireless communications channel assignments in the plurality of wireless communications channel assignments.

13. An apparatus, comprising:

means for selecting a first plurality of sets of wireless communications channels from a band of wireless communications frequencies;

means for determining a power for each set of the first plurality of sets of wireless communications channels;

means for ordering the first plurality of sets of wireless communications channels by power to form an ordered plurality of sets of wireless communications channels;

means for selecting from the ordered plurality of sets of wireless communications channels, sets of wireless communications channels that satisfy a power criteria to form a second plurality of sets of wireless communications channels;

means for determining each possible assignment of channels in the set to transmitters for each set of the second plurality of sets of wireless communications channels;

means for determining a separation between the channels for each possible assignment of channels in the set to transmitters;

means for determining whether the separation satisfies a specified separation criteria for each possible assignment of channels in the set to transmitters;

means for adding possible assignment of channels in the set to transmitters to a plurality of candidate channel to transmitter assignments, if the possible assignment of channels in the set to transmitters satisfies the specified separation criteria;

means for determining an overall interference generated by each one of the plurality of candidate channel to transmitter assignments; and

means for choosing a candidate channel to transmitter assignment that reduces the overall interference.

14. A wireless access point for providing wireless access to a wired network within a building, the wireless access point comprising:

a first antenna arrangement configured to communicate with wireless devices within a first section of a spatial area around the wireless access point, wherein the first antenna arrangement is further configured to determine whether a first communications channel assigned to the first section of the spatial area is currently being used to carry communication signals before transmitting any communication signals onto the first communications channel;

a second antenna arrangement configured to communicate with wireless devices within a second section of a spatial area around the wireless access point, wherein the second antenna arrangement is further configured to determine whether a second communications channel assigned to the second section of the spatial area is currently being used to carry communication signals before transmitting any communication signals onto the second communications channel; and

a management mechanism configured to manage the operation of the first and second antenna arrangements and to assign channels to the first spatial area and the second spatial area according to a particular wireless communications channel assignment selected from a plurality of wireless communications channel assignments, wherein the particular wireless communications channel assignment provides less interference relative to other wireless communications channel assignments in the plurality of wireless communications channel assignments.

15. An antenna apparatus configured to enable selective wireless communications with wireless devices located in a plurality of sections of a spatial area around the antenna apparatus, the antenna apparatus comprising:

a central metal reflector; and

a plurality of metal septums extending outward from the central metal reflector into the spatial area around the antenna apparatus to define the plurality of sections;

wherein frequencies are allocated to each of the plurality of sections in accordance with a channel to section assignment determined from a set of potential channel to section assignments for available channels by selecting one of the channel to section assignments having a lower overall interference relative to other channel to section assignments.

16. The antenna apparatus as recited in claim 15, further comprising:

a first radiating assembly disposed between the plurality of metal septums to provide wireless communications with the first set of wireless devices in the first section; and

a second radiating assembly disposed between the plurality of metal septums to provide wireless communications with the second set of wireless devices in the second section.

17. The antenna apparatus as recited in claim 16, wherein the first radiating assembly comprises a first patch element having a first radiating element configured to transmit in a first frequency band.

18. The antenna apparatus as recited in claim 17, wherein the first radiating element is further configured to transmit in a second frequency band.

19. The antenna apparatus as recited in claim 17, wherein the first radiating assembly comprises a second patch element having a second radiating element, wherein the second patch element is oriented with respect to the first patch element to provide polarization diversity.

20. The antenna apparatus as recited in claim 16, wherein the first and second radiating assemblies are separated by a specified distance and the antenna apparatus is configured to select the first or second antenna apparatus to transmit or receive an RF signal.

21. The antenna apparatus as recited in claim 17, wherein the first radiating assembly comprises a second patch element having a second radiating element, wherein the second patch element is oriented with respect to the first patch element to provide polarization diversity.

22. The antenna apparatus as recited in claim 21, wherein the second patch element is oriented at about ninety degrees with respect to the first patch element.

23. A wireless access point, comprising:

an antenna configured to send and receive communications signals on a first communications channel within a first section of a spatial area on a first frequency and to send and receive communications signals on a second communications channel within a second section of the spatial area on a second frequency; and

a management mechanism configured to assign the first and second frequencies to the first and second spatial areas in accordance with a channel sector assignment determined from a set of potential channel to sector assignments for available channels by selecting one of the channel to sector assignments having a lower overall interference relative to other channel to sector assignments.

24. The wireless access point as recited in claim 23, wherein the management mechanism is further configured to assign varying polarization to each of the first and second sectors, thereby enabling reduced interference between the first sector and the second sector.

25. A wireless communications system comprising:

a first antenna arrangement having a first transceiver configured to transmit and receive communications signals on a communications channel within a first section of a spatial area around the wireless communications apparatus;

a second antenna arrangement having a second transceiver configured to transmit and receive communications signals on the communications channel within a second section of the spatial area around the wireless communications apparatus; and

wherein frequencies are allocated to each of the plurality of sections in accordance with a channel to sector assignment determined from a set of potential channel to sector assignments for available channels by selecting one of the channel to sector assignments having a lower overall interference relative to other channel to sector assignments.

26. A computer readable medium carrying one or more sequences of instructions for determining an assignment of wireless communications channels to a plurality of wireless communications transmitters, which instructions, when executed by one or more processors, cause the one or more processors to carry out the steps of:

determining a plurality of available wireless communications channels;

determining a plurality of wireless communications channel assignments based upon the plurality of available wireless communications channels and a number of wireless communications transmitters in the plurality of wireless transmitters; and

selecting from the plurality of wireless communications channel assignments, a particular wireless communications channel assignment that provides less interference relative to other wireless communications channel assignments in the plurality of wireless communications channel assignments.

27. A computer-readable medium carrying one or more sequences of instructions for determining an assignment of wireless communications channels to a plurality of wireless communications transmitters, which instructions, when executed by one or more processors, cause the one or more processors to carry out the steps of:

determining available wireless communications channels by;

selecting a first plurality of sets of wireless communications channels from a band of wireless communications frequencies;

determining a power for each set of the first plurality of sets of wireless communications channels;

ordering the first plurality of sets of wireless communications channels by power to form an ordered plurality of sets of wireless communications channels; and

selecting from the ordered plurality of sets of wireless communications channels, sets of wireless communications channels that satisfy a power criteria to form a second plurality of sets of wireless communications channels;

determining channel to transmitter assignments by;

for each set of the second plurality of sets of wireless communications channels, determining each possible assignment of channels in the set to transmitters;

for each possible assignment of channels in the set to transmitters, determining a separation between the channels;

for each possible assignment of channels in the set to transmitters, determining whether the separation satisfies a specified separation criteria; and

adding possible assignment of channels in the set to transmitters to a plurality of candidate channel to transmitter assignments, if the possible assignment of channels in the set to transmitters satisfies a specified separation criteria; and

selecting a channel to transmitter assignment by;

determining an overall interference generated by each one of the plurality of candidate channel to transmitter assignments; and

choosing a candidate channel to transmitter assignment that reduces the overall interference.