Method of modeling a CDMA cellular telephone system

• US 6,424,643 B1
• Filed: 03/08/1999
• Issued: 07/23/2002
• Est. Priority Date: 03/08/1999
• Status: Expired due to Fees

• Current Assignee: Allen Telecom LLC (CommScope Holding Company, Inc.)
• Original Assignee: Scoreboard Inc. (CommScope Holding Company, Inc.)
• Inventors: Gutowski, Stanley
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): PHAN, MAN U
• Application Number:
  US09/263,572
• Time in Patent Office: 1,233 Days
• Field of Search: 370/342, 370/341, 370/340, 370/335, 370/329, 370/327, 370/320, 370/344, 370/337, 370/201, 370/479, 455/62, 455/63, 455/69, 455/422, 455/425, 455/450, 455/452, 455/455, 455/522
• US Class Current: 370/342
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

A computer implemented process which utilizes actual received signal level data gathered from closely spaced locations covering an entire CDMA system to calculate interference levels at each location, determines those base stations which most probably communicate with a mobile unit at each particular location, compiles a list of neighbor base stations for each base station at each location throughout the system, and determines the transmit power necessary for each base station to communicate with a mobile unit at each location, calculates interference levels at each base station, and determines the transmit power necessary for a mobile unit at each location to communicate with each base station which most probably communicates with a mobile unit at that particular location.

Claims

1. A process for modeling a CDMA cellular telephone system comprising the steps of:

determining base stations likely to communicate with a mobile unit at each of a plurality of closely spaced locations defining all positions of some area of a CDMA system at which a mobile unit is likely to communicate with base stations utilizing data indicating received signal level at each location and associated transmit power of each base station throughout the area;

determining the transmit power necessary for each base station to communicate effectively with a mobile unit at each location throughout the area;

calculating interference levels at each base station by determining a level of decoded transmission necessary to provide a quality signal at each base station, multiplying the level of decoded transmission determined for each location by a probability of a base station serving the location, and summing results determined from the multiplications;

repeating the forgoing steps of the process until transmit power for each base station does not change significantly from a preceding iteration of the process;

then

determining transmit power necessary for a mobile unit at each location to communicate with each base station which most probably communicates with a mobile unit at that particular location; and

repeating the steps of the process for determining transmit power for each mobile unit until a total interference level at each base station does not change significantly from a preceding iteration of the process.

2. A computer implemented system for modeling characteristics of a cellular telephone system, comprising:

means for utilizing data gathered at closely-spaced locations throughout an area of the cellular telephone system being modeled to determine a base station most likely to serve each location and neighbor list of base stations for each base station most likely to serve each location;

means for utilizing data gathered at closely-spaced locations throughout an area of the cellular telephone system being modeled to determine rapidly transmit power required by a mobile unit at each location to communicate with each base station likely to serve such location, which comprises;

means for determining a transmit power using a total base level received signal power at all locations with which a base station is likely to serve;

means for determining a transmit power using total received signal power at all locations with which a base station is likely to serve to produce quality received signals from all locations with which a base station is likely to serve which comprises means for determining a received signal level sufficient to provide a quality signal at a location for a total base level received signal and means for determining a transmit power at a base station to produce the quality signal at a location; and

means for redetermining a transmit power using total received signal power to produce quality received signals at all locations with which a base station is likely to serve until a difference between sequential transmit powers becomes insignificant; and

means for utilizing data gathered at closely-spaced locations throughout an area of the cellular telephone system being modeled to determine rapidly transmit power required by a mobile unit at each location to communicate with each base station likely to serve such location.