Course-255

Introduction: Interference to CDMA systems

Forward and Reverse Link Vulnerability Characteristics

I. Basics of Noise and CDMA Capacity

a. The Thermal Noise Floor and channel bandwidth

b. Actual Receiver Sensitivity: Noise Figure

c. Reverse Link Noise Floor Rise due to Traffic

d. Noise floor versus capacity and users at edge

II. A Quick Look at Receiver Characteristics

a. Superheterodyne Receivers and Image Rejection

III. Recognizing Interference When It Occurs

a. Forward Link Clues

b. Reverse Link Clues

c. Reverse Link Vulnerability – interference range

d. Using BTS noise floor rise as an interference indicator

IV. Finding the Interference Source

a. Reverse Link Techniques

i. Identify affected sectors

ii. Spectrum analyzer search techniques and pitfalls

iii. Human factors: company procedure, political concerns,

regulatory support

b. Common Interference Sources and their characteristics

c. Locating sources with successive triangulation

d. Antenna, amplifier, and filter considerations

V. Interference and Other Problems With System Elements

a. Tower-Mounted Amplifiers

b. Reradiators

c. In-Building Systems

d. Site Configuration Guidelines

VI. Intermodulation

a. Intermodulation Interference Analysis by Core RF tools

b. Transmitter Noise Analysis

c. Receiver Desensitization Analysis

d. Transmitter Spurious Output Interference Analysis

VII. External Interference Sources

a. Potential Harmonic Generators

b. Ultra-WideBand Communications

c. Interference to/from GPS reception

d. Wi-Fi and other LAN technologies, cordless phones

e. Bluetooth Technology; MMDS

VIII. Some Notable Interference Sources

IX. Interference Measurement Tools

X. Optional Second Day: Real-world Exercises