Radio network test analysis system

• US 6,754,487 B1
• Filed: 08/15/2000
• Issued: 06/22/2004
• Est. Priority Date: 02/28/2000
• Status: Expired

• Current Assignee: PCTEL, Inc.
• Original Assignee: Telcom Network Optimization LLC
• Inventors: Sanders, Alan David, Linder, Perry Simon Lewars, Pickering, Leslie Westhaver, Dickherber, Anthony Jerome, Floyd, Timothy Scott, Pratt, Thomas Gregory
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): TRAN, TUAN A
• Application Number:
  US09/638,921
• Time in Patent Office: 1,407 Days
• Field of Search: 455/423, 455/424, 455/425, 455/434, 455/524, 455/525, 455/67.11, 455/161.1, 455/161.2, 455/226--22, 455/229, 375/254, 375/285, 375/343, 375/347, 375/350, 375/349
• US Class Current: 455/423
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

Optimization of a cellular network is facilitated by an apparatus that performs drive test measurements of a cellular network to identify co-channel interference. The co-channel interference is identified by measuring the signal strengths at various locations within a cell sector and analyzing the recorded information. A key aspect of the invention is synthesizing the received signals to identify the cellular transmitters originating the signals. If signal energy is detected from more than one cellular transmitter on a single frequency, the co-channel interference is identified. This process is particular well suited within a GSM cellular system by detecting the transmission of forward control channel messages and using the information within the forward control channel messages to identify the origination cellular transmitters.

Claims

1. A method of correlating transmission data received from cellular transmitting devices, the method comprising the steps of:

receiving a first stream of transmission data having a first received signal frequency for a first period of time;

correlating the first transmission data against a signal template to identify a first FCCH burst frame;

identifying first FCCH time data corresponding to the first FCCH burst frame;

receiving a second stream of transmission data having a second received signal frequency for a second period of time;

correlating the second transmission data against a signal template to identify a second FCCH burst frame;

identifying second FCCH time data corresponding to the second FCCH burst frame; and

analyzing the first FCCH time data and the second FCCH time data to determine whether the first FCCH time data correlates to the second FCCH time data.

2. The method of claim 1, further comprising the steps of:

identifying a first training sequence received as part of the first stream of transmission data; and

identifying a first base station color code associated with the first training sequence.

3. The method of claim 2, further comprising the step of:

identifying a transmitting base station associated with the first base station color code.

4. The method of claim 1, wherein the first FCCH time data corresponds to the second FCCH time data if the second FCCH time data represents a time frame occurring a multiple of 51 time frames apart from the first FCCH time data.

5. The method of claim 1, wherein the first FCCH time data corresponds to the second FCCH time data if the second FCCH time data represents a time frame occurring 10 time frames from a time frame occurring a multiple of 51 time frames apart from the first FCCH time data.

6. The method of claim 1, wherein the first FCCH time data corresponds to the second FCCH time data if the second FCCH time data represents a time frame occurring 11 time frames from a time frame occurring a multiple of 51 time frames apart from the first time data.

7. The method of claim 1, wherein the first FCCH time data corresponds to the second FCCH time data if the second FCCH time data represents a time frame occurring 20 time frames from a time frame occurring a multiple of 51 time frames apart from the first time data.

8. The method of claim 1, wherein the first FCCH time data corresponds to the second FCCH time data if the second FCCH time data represents a time frame occurring 21 time frames from a time frame occurring a multiple of 51 time frames apart from the first time data.

9. The method of claim 1, where the first period of time is of sufficient duration to record sixty-two frames of transmission data.

10. The method of claim 1, wherein the signal template comprises an FCCH Burst and a SYNCH training sequence.

11. The method of claim 1, further comprising the steps of:

identifying the first signal frequency of the first stream of transmission data; and

identifying the second signal frequency of the second stream of transmission data.

12. The method of claim 11, further comprising the steps of:

determining that the first and second streams of transmission data were sent from the same base station if the first FCCH time data correlates to the second FCCH time data and the first signal frequency is approximately equal to the second signal frequency.

13. The method of claim 1, further comprising the step of:

determining that the first and second streams of transmission data were transmitted from the same base station if the first FCCH time data correlates to the second FCCH time data.