Up-link channel assignment scheme for cellular mobile communications systems employing multi-beam antennas with beam selection

• US 5,590,399 A
• Filed: 02/23/1995
• Issued: 12/31/1996
• Est. Priority Date: 02/23/1995
• Status: Expired due to Term

• Current Assignee: Nextel Communications (Deutsche Telekom AG)
• Original Assignee: Nextel Communications (Deutsche Telekom AG), NTT Mobile Communications Network Inc. (Nippon Telegraph and Telephone Corporation)
• Inventors: Nishioka, Seiji, Matsumoto, Tadashi
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Nguyen, Lee
• Application Number:
  US08/393,210
• Time in Patent Office: 677 Days
• Field of Search: 455/33.1, 455/33.2, 455/33.3, 455/33.4, 455/34.1, 455/34.2, 455/54.1, 455/56.1, 455/62, 455/63, 379/59, 379/60, 375/348
• US Class Current: 455/449
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 36/00 Hand-off or reselection arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

An up-link channel assignment scheme for cellular mobile communications systems employing multibeam antennas with beam selection, in which a channel that is selected from among all variable channels in the same frequency band may be assigned to each of the antenna beams in a base station for communications. Channel selection for a base station takes place independently of that for other cells, such that the process is autonomous. Channel selection is based upon an estimate of the signal-to-interference power ration ("SIR") in which a channel having the smallest SIR estimate that is larger than or equal to a given threshold value is chosen. Alternatively, a channel having the largest SIR estimate is selected.

Claims

1. A channel assignment method for a cellular mobile communications system having a multibeam antenna system with beam selection, the method comprising the steps of:

estimating with said antenna a signal-to-interference power ratio ("SIR") for each channel in said cellular communications system by measuring Euclidean distance between a desired signal and a received signal and by averaging said measured distance over several samples;

using said averaged Euclidean distance as a signal quality measure; and

assigning by said antenna a communications channel to each antenna beam of said multibeam system at a cell within said cellular system independently of other cells within said cellular system based upon an SIR derived value by initiating a hand-off process if said quality measure expressed by the averaged Euclidean distance becomes worse than a selected threshold level, selecting a hand-off destination channel from among all available channels in frequency band, and measuring a received composite signal power of the other channels at a base station receiver to determine said hand-off destination.

2. The method of claim 1, wherein said channel assignment step selects a channel having the smallest SIR estimate that is larger than or equal to a selected threshold value.

3. The method of claim 1, wherein said channel assignment step selects a channel having a largest SIR estimate.

4. The method of claim 1, wherein said channel assignment step keeps using the same channel if there are no channels having an SIR estimate larger than a selected threshold value.

5. The method of claim 1, wherein said channel assignment step selects any of a channel having the smallest SIR estimate that is larger than or equal to a selected threshold value, and a channel having a largest SIR estimate;

and wherein said channel assignment step keeps using the same channel if there are no channels having an SIR estimate larger than said selected threshold value.

6. An up-link channel assignment apparatus for cellular mobile communications systems employing multi-beam antenna with beam selection, said apparatus comprising:

means for estimating with said antenna a signal-to-interference power ratio ("SIR") for each channel in said cellular communications system, wherein said estimating means further comprises means for measuring Euclidean distance between a desired signal and a received signal, means for averaging said measured distance over several samples, and means for using said averaged Euclidean distance as a signal quality measure; and

means for assigning by said antenna a communications channel to each antenna beam of said multibeam system at a cell within said cellular system independently of other cells within said cellular system based upon an SIR derived value, wherein said assigning means further comprises means for initiating a hand-off process if said signal quality measure expressed by the averaged Euclidean distance becomes worse than a selected threshold level, means for selecting a hand-off destination channel from among all available channels in a frequency band, and means for measuring a received composite signal power of the other channels at a base station receiver to determine said hand-off destination.

7. The apparatus of claim 6, wherein said channel assignment means selects a channel having the smallest SIR estimate that is larger than or equal to a selected threshold value.

8. The apparatus of claim 6, wherein said channel assignment means selects a channel having a largest SIR estimate.

9. The apparatus of claim 6, wherein said channel assignment means keeps using the same channel if there are no channels having an SIR estimate larger than a selected threshold value.

10. The apparatus of claim 6, wherein said channel assignment means selects any of a channel having the smallest SIR estimate that is larger than or equal to a selected threshold value, and a channel having a largest SIR estimate;

and wherein said channel assignment means keeps using the same channel if there are no channels having an SIR estimate larger than said selected threshold value.