Abstract
The concept of overlay in radio communication systems has been around for some time with particular emphasis on terrestrial links and spectral sharing between spread spectrum and existing narrowband services. We present an analysis regarding a direct sequence code division multiple access (CDMA) and narrowband frequency division multiple access (FDMA) overlay in a satellite environment and discuss models which describe the behaviour of the mutual interference to both systems. Although a CDMA system has an inherent resistance to jamming, an FDMA system with a large number of active users constitutes a severe interference problem for successful operation. Fortunately, a CDMA design affords some flexibility in parameters such as centre frequency, spread rate and power level which can be chosen by the designer in response to different FDMA implementations. We present results for various FDMA frequency allocations within the overlay and discuss the impact of coding and conforming to existing International Telecommunications Union (ITU) regulations. >
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
