Title :
CDMA transmitter filtering for cellular overlay systems
Author :
Rainbolt, Bradley J. ; Miller, Scott L.
Author_Institution :
Dept. of Electr. & Comput. Eng., Florida Univ., Gainesville, FL, USA
fDate :
2/1/2000 12:00:00 AM
Abstract :
In this paper, the overlay of a code-division multiple-access (CDMA) cellular system in a frequency band which is already providing service to a narrow-band cellular system is investigated. The motivation for this study is to demonstrate the potential of CDMA overlay as an efficient method for making a long-term transition from narrow-band cellular to CDMA cellular. For the single cell case, it was shown by Rainbolt and Miller (see IEEE J. Select. Areas Commun., vol.16, p.1756-64, 1998) that interference caused to the narrow-band system by even a lightly-loaded CDMA system is significant, a problem which can be greatly alleviated through the use of notch filtering in the CDMA transmitters to avoid active narrow-band users. Similar conclusions will be reached in this paper for the cellular case. The effects of notching on CDMA performance will be looked at in detail, and it will be shown that the notching is less of a problem than is the narrow-band interference inherent in overlay systems
Keywords :
AWGN channels; cellular radio; channel capacity; code division multiple access; filtering theory; interference suppression; multiuser channels; notch filters; radio transmitters; radiofrequency interference; AWGN channel; CDMA cellular systems; CDMA overlay; CDMA transmitter filtering; additive white Gaussian noise channel model; cellular overlay systems; code-division multiple-access; frequency band; interference; narrow-band capacity; narrow-band cellular system; narrow-band interference; notch filtering; Bandwidth; Filtering; Frequency; Helium; Interference; Multiaccess communication; Narrowband; Signal processing; Spread spectrum communication; Transmitters;
Journal_Title :
Communications, IEEE Transactions on
