Simulating user interference in a spread spectrum communication network

Soliman

[54] SIMULATING USER INTERFERENCE IN A SPREAD SPECTRUM COMMUNICATION NETWORK

[75] Inventor: Samir S. Soliman, San Diego, Calif.

[73] Assignee: Qualcomm Incorporated, San Diego, Calif.

[21] Appl. No.: 601,491

[22] Filed: Feb. 14, 1996

Related U.S. Application Data

[63] Continuation of Ser. No. 274,611, Jul. 13, 1994, abandoned.

[51] Int. CI.6 H04J 13/02

[52] U.S. CI 370/252; 370/335; 375/200;

455/67.3

[58] Field of Search 370/13. 17, 18.

370/252. 320. 335, 342, 479; 375/200-210; 380/34; 455/1. 33.1, 53.1. 54.1, 67.1. 67.3.

67.4, 115

[56] References Cited

U.S. PATENT DOCUMENTS

3,806,809 4/1974 Firman 455/115

4,317,214 2/1982 Attinello 455/1

5,220,680 6/1993 Lee 455/1 X

5,233,628 8/1993 Rappaport et al 375/224

5,596,570 1/1997 Soliman 370/252

Primary Examiner—Melvin Marcelo

Attorney, Agent, or Firm—Russell B. Miller; Gregory D.

Ogrod

[57] ABSTRACT

A method and apparatus for simulating signal interference within a communication system, such wireless or cellular communication systems. The communication system is preferably of a type in which code division multiple access (CDMA) spread spectrum communication signals are used. The method for simulating signal interference power received by a base station receiver includes estimating a first composite signal power corresponding to the sum of signal power transmitted by a first set of simulated users located in a first cell. An estimate is also made of a first normalized date rate for transmission of the composite signal. A first interference signal is then generated at a power level determined on the basis of the first composite signal power and normalized data rate. In a preferred implementation, the first interference signal power is adjusted in accordance with an average power fluctuation arising as a consequence of closed loop power control. Further, a second composite signal power is determined by estimating the sum of signal power transmitted by a second set of simulated users located outside of the first cell. A similar estimate is made of a second normalized data rate at which this signal power is transmitted by the second set of simulated users. This allows the generation of a second interference signal based on the second composite signal power and normalized data rate. Generation of the first interference signal will typically involve synthesis of electrical noise over a predetermined frequency band. The power of the electrical noise is then adjusted in accordance with the product of the first composite signal power and the first normalized data rate.

50 Claims, 7 Drawing Sheets