Title :
Cochannel uplink interference in PN spread QPSK satellite systems
Author :
Frank, Joseph ; Kim, Yong H.
Author_Institution :
Dept. of Electr. & Comput. Eng., New Jersey Inst. of Technol., Newark, NJ, USA
Abstract :
The effect of a bandpass limiter in code division multiple access quadriphase shift keying (QPSK) satellite spread spectrum communication systems is investigated. The case of a cochannel interferer on the uplink is analyzed in detail. The nonlinear characteristics of the bandpass limiter result in the generation of intermodulation products which become narrowband signals after the despreading process in the spread spectrum receiver. These intermodulation products and the cochannel interference affect system performance. The assumptions made in deriving the theoretical performance of the system were checked by simulating the entire system using the Block Oriented Systems Simulator (BOSS) software package. The results of the simulation show good agreement with the theoretical calculations, within 1 to 2 dB in signal-to-noise ratio. In addition, by means of simulation, it was possible to explore some features of the system that could not be addressed analytically, such as the effect of processing gain and unbalanced codes on system performance
Keywords :
code division multiple access; digital simulation; phase shift keying; radiofrequency interference; satellite relay systems; spread spectrum communication; telecommunications computing; Block Oriented Systems Simulator; QPSK satellite systems; bandpass; cochannel uplink interference; code division multiple access quadriphase shift keying; intermodulation products; narrowband signals; processing gain; pseudonoise; software package; spread spectrum communication systems; unbalanced codes; Artificial satellites; Character generation; Communication systems; Interference; Multiaccess communication; Narrowband; Quadrature phase shift keying; Signal generators; Spread spectrum communication; System performance;
Conference_Titel :
Military Communications Conference, 1992. MILCOM '92, Conference Record. Communications - Fusing Command, Control and Intelligence., IEEE
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-0585-X
DOI :
10.1109/MILCOM.1992.244105
