System and method for adaptive channel allocation

• US 6,078,812 A
• Filed: 12/15/1997
• Issued: 06/20/2000
• Est. Priority Date: 12/15/1997
• Status: Expired due to Term

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Mintz, Yaron
• Primary Examiner(s): Hunter, Daniel S.
• Assistant Examiner(s): ZEWDU, MELESS NMN
• Application Number:
  US08/990,439
• Time in Patent Office: 918 Days
• Field of Search: 455/62, 455/63, 455/67.3, 455/450, 455/452, 455/509, 455/161.1, 455/161.2, 455/561, 455/562, 455/434
• US Class Current: 455/434
• CPC Class Codes: H04W 16/16 for PBS [Private Base Station] arrangements
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A telecommunications system and method is disclosed for providing adaptive channel allocation for indoor cellular systems, which utilizes interference measurements on both the down-link channels and the up-link channels. This can be accomplished by using a Stand Alone Dual Channel Scanner (SADCS) to assist indoor cellular systems in allocating traffic channels on the basis of interference from external systems, which measures both the up-link and the down-link at the same time. A number of SADCSs can be placed at strategically located points in the building to measure interference on a channel by channel basis, and to communicate the results to the indoor base station, which can then allocate traffic channels with high confidence of maintaining a good speech quality.

Claims

1. A telecommunications system for an indoor wireless system having a plurality of channels, each of said channels having a respective up-link frequency and down-link frequency associated therewith, said telecommunications system comprising:

a receiving antenna adapted to receive a plurality of frequencies associated with said indoor system;

at least one scanner connected to said receiving antenna and adapted to receive said plurality of frequencies from said receiving antenna, filter said plurality of frequencies to select said respective up-link and down-link frequencies associated with a given one of said plurality of channels, and measure an interference value for each of said selected up-link and down-link frequencies; and

a base station within said indoor system, said base station being remotely connected via a cable to said scanner said base station being adapted to receive a highest one of said interference values associated with said at least one channel from said at least one scanner and determine a least interference one of said plurality of channels using said highest interference value.

2. The telecommunications system of claim 1, further comprising a microprocessor adapted to determine said given channel, receive said highest interference value and send said highest interference value to said base station.

3. The telecommunications system of claim 2, wherein said microprocessor determines a phase lock loop frequency associated with said given channel, said phase lock loop frequency being sent to a phase lock loop node within said scanner, said respective up-link and down-link frequencies associated with said given channel being selected using said phase lock loop node.

4. The telecommunications system of claim 3, wherein said phase lock loop frequency is 45 megahertz below said selected up-link frequency associated with said given channel.

5. The telecommunications system of claim 4, wherein said scanner further comprises a splitter, said receiving antenna being adapted to send said plurality of frequencies to said splitter, said splitter being adapted to split said plurality of frequencies into an up-link path and a down-link path, each of said up-link frequencies being on said up-link path, each of said down-link frequencies being on said down-link path.

6. The telecommunications system of claim 5, wherein said scanner further comprises first and second filters, said first filter being on said up-link path, said second filter being on said down-link path, said first and second filters being adapted to eliminate extraneous ones of said up-link and down-link frequencies respectively.

7. The telecommunications system of claim 6, wherein said scanner further comprises first and second amplifiers, said first amplifier being connected to said first filter, said second amplifier being connected to said second filter, said first and second amplifiers being adapted to amplify said filtered up-link and down-link frequencies respectively.

8. The telecommunications system of claim 7, wherein said scanner further comprises first and second mixers connected to said first and second amplifiers respectively, said phase lock loop node being connected to said first and second mixers, said phase lock loop node being adapted to select said up-link and down-link frequencies associated with said given channel, said first mixer adapted to mix said selected up-link frequency down to 45 megahertz, said second mixer adapted to mix said selected down-link frequency down to 90 megahertz.

9. The telecommunications system of claim 8, wherein said scanner further comprises third and fourth filters, said third filter being connected to said first mixer, said fourth filter being connected to said second mixer, said third and fourth filters being adapted to filter intermodulation products from said selected up-link frequency and said selected down-link frequency respectively.

10. The telecommunications system of claim 9, wherein said scanner further comprises first and second strength indicator stages connected to said third and fourth filters respectively adapted to measure said interference values associated with said selected up-link frequency and said selected down-link frequency, respectively.

11. The telecommunications system of claim 1, wherein said scanner comprises a maximum node adapted to determine said highest interference value.

12. The telecommunications system of claim 1, wherein said scanner is adaptive to determine additional interference values associated with additional ones of said channels and send said addition interference values to said base station, said least interference channel selected by said base station having the lowest value of said additional interference values and said highest interference value.

13. The telecommunications system of claim 1, further comprising second, third, and fourth scanners for determining second, third, and fourth interference values respectively, said base station determining said least interference channel using the highest of said highest, second, third and fourth interference values.

14. The telecommunications system of claim 1, further comprising a mobile terminal in wireless communication with said base station, said base station allocating said least interference channel for use by said mobile terminal.

15. A method for determining a least interference one of a plurality of channels within an indoor wireless system, each of said plurality of channels having an up-link frequency and a down-link frequency associated therewith, said method comprising the steps of:

determining, a given one of a plurality of said channels to be scanned;

transmitting a plurality of frequencies associated with said indoor system from a receiving antenna to at least one scanner;

selecting, by said scanner, said respective up-link and down-link frequencies associated with said given channel;

sending, a highest one of said interference values from said scanner to a base station within said indoor system and remotely connected to said scanner via a cable; and

determining, by said base station, said least interference channel, using said highest interference value.

16. The method of claim 15, further comprising, after said step of determining said given channel, the steps of:

determining, a phase lock loop frequency associated with said given channel; and

sending, said phase lock loop frequency to a phase lock loop node within said scanner, said step of selecting said respective up-link and down-link frequencies associated with said given channel being performed using said phase lock loop node.

17. The method of claim 16, wherein said phase lock loop frequency is 45 megahertz below said selected up-link frequency.

18. The method of claim 17, wherein said scanner further comprises a splitter, and further comprising, after said step of transmitting, the step of:

splitting, by said splitter, said plurality of frequencies into an up-link path and a down-link path, each of said up-link frequencies being on said up-link path, each of said down-link frequencies being on said down-link path.

19. The method of claim 18, wherein said scanner further comprises first and second filters, said first filter being on said up-link path, said second filter being on said down-link path, and further comprising, before said step of selecting, the step of:

filtering, by said first and second filters, extraneous ones of said up-link and down-link frequencies respectively.

20. The method of claim 19, wherein said scanner further comprises first and second amplifiers, said first amplifier being connected to said first filter, said second amplifier being connected to said second filter, and further comprising, after said step of filtering, the step of:

amplifying, by said first and second amplifiers, said filtered up-link and down-link frequencies respectively.

21. The method of claim 20, wherein said scanner further comprises first and second mixers connected to said first and second amplifiers respectively, said phase lock loop node being connected to said first and second mixers, said step of selecting being performed by said phase lock loop node selecting said respective up-link frequency and said respective down-link frequency associated with said given channel, and further comprising, after said step of selecting, the steps of:

mixing, by said first mixer, said selected up-link frequency down to 45 megahertz; and

mixing, by said second mixer, said selected down-link frequency down to 90 megahertz.

22. The method of claim 21, wherein said scanner further comprises third and fourth filters, said third filter being connected to said first mixer, said fourth filter being connected to said second mixer, and further comprising, after said steps of mixing, the step of:

filtering, by said third and fourth filters, intermodulation products from said selected up-link frequency and said selected down-link frequency respectively.

23. The method of claim 22, wherein said scanner further comprises first and second strength indicator stages connected to said third and fourth filters respectively, said step of measuring said interference values associated with said selected up-link frequency and said selected down-link frequency being performed by said first and second strength indicator stages respectively.

24. The method of claim 15, further comprising, before said step of determining said least interference channel, the steps of:

determining, by said scanner, additional interference values associated with additional ones of said channels; and

sending, said additional highest interference values from said scanner to said base station, said least interference channel having the lowest value of said additional interference values and said highest interference value.

25. The method of claim 15, further comprising, before said step of determining said least interference channel, the step of:

determining, by second, third, and fourth scanners, second, third, and fourth interference values respectively; and

sending, by said second, third, and fourth scanners, said second, third, and fourth highest interference values respectively to said base station, said step of determining said least interference channel being performed by said base station using the highest of said highest, second, third and fourth interference values.

26. The method of claim 15, further comprising, after said step of determining said least interference channel, the step of:

allocating, by said base station, said least interference channel for use by a mobile terminal in wireless communication with said base station.

27. A scanner adapted to determine a highest interference value associated with a given one of a plurality of channels within an indoor wireless telecommunications system, said given channel having an up-link frequency and a down-link frequency associated therewith, said scanner comprising:

connection means for remotely connecting via a cable to a base station within said indoor wireless telecommunications system;

receiving means for receiving a signal comprising a plurality of frequencies associated with said indoor system;

a splitter for splitting said signal into up-link and down-link paths;

frequency selection means for selecting said up-link frequency associated with said given channel from said up-link path and said down-link frequency associated with said given channel from said down-link path;

interference measuring means for measuring a first interference value for said selected up-link frequency and a second interference value for said selected down-link frequency; and

maximum selection means for selecting said highest interference value, said highest interference value being the maximum of said first and second interference values, said highest interference values being sent to said base station.

28. The scanner of claim 27, further comprising a phase lock loop node adapted to receive a phase lock loop frequency associated with said given channel, said frequency selection means comprising said phase lock loop node.

29. The scanner of claim 28, wherein said phase lock loop frequency is 45 megahertz below said selected up-link frequency.

30. The scanner of claim 29, further comprising first and second filters, said first filter being on said up-link path, said second filter being on said down-link path, said first and second filters being adapted to eliminate extraneous ones of said frequencies on said up-link and down-link paths respectively.

31. The scanner of claim 30, further comprising first and second amplifiers, said first amplifier being connected to said first filter, said second amplifier being connected to said second filter, said first and second amplifiers being adapted to amplify said filtered frequencies on said up-link and down-link paths respectively.

32. The scanner of claim 31, further comprising first and second mixers connected to said first and second amplifiers respectively, said phase lock loop node being connected to said first and second mixers, said frequency selection means comprising said phase lock loop node selecting said up-link frequency and said down-link frequency associated with said given channel, said first mixer being adapted to mix said selected up-link frequency down to 45 megahertz, said second mixer being adapted to mix said selected down-link frequency down to 90 megahertz.

33. The scanner of claim 32, further comprising third and fourth filters, said third filter being connected to said first mixer, said fourth filter being connected to said second mixer, said third and fourth filters being adapted to filter intermodulation products from said selected up-link frequency and said selected down-link frequency respectively.

34. The scanner of claim 33, wherein said interference measuring means comprises first and second strength indicator stages connected to said third and fourth filters respectively adapted to measure said first interference value associated with said selected up-link frequency and said second interference value associated with said selected down-link frequency respectively.

35. The scanner of claim 27, wherein said maximum selection means comprises a maximum node for determining said highest interference value.