Title :
A new family of modulation schemes for land mobile radio
Author :
Ramésh, R. ; Toy, R.L. ; Koilpillai, R.D. ; Chennakeshu, S.
Author_Institution :
Ericsson Inc., Research Triangle Park, NC, USA
Abstract :
Achievable spectral efficiency in land-mobile radio (LMR) systems is limited by adjacent-channel interference (ACI) specifications. Spectral efficiency can be improved by using digital modulation schemes. With linear modulation schemes, intermodulation products produced by non-linear power amplifiers lead to increased ACI. In this paper, a new family of linear modulation schemes called envelope-constrained modulation schemes is introduced to improve the spectral efficiency of LMR systems using quasilinear power amplifiers. These modulation schemes exhibit low envelope variations and thus ease the linearity requirements on the power amplifier. Also, power savings can be realized by incorporating coded modulation. An analytical evaluation of the performance is performed to illustrate the gain achievable using the new modulation schemes
Keywords :
adjacent channel interference; intermodulation; land mobile radio; modulation coding; power amplifiers; radiofrequency interference; ACI; LMR systems; adjacent-channel interference; coded modulation; digital modulation schemes; envelope-constrained modulation schemes; gain; intermodulation products; land mobile radio; linear modulation schemes; linearity requirements; low envelope variations; nonlinear power amplifiers; performance; power savings; quasilinear power amplifiers; spectral efficiency; Base stations; Batteries; Digital modulation; Frequency modulation; Land mobile radio; Linearity; Modulation coding; North America; Power amplifiers; Protection;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 1995. PIMRC'95. Wireless: Merging onto the Information Superhighway., Sixth IEEE International Symposium on
Conference_Location :
Toronto, Ont.
Print_ISBN :
0-7803-3002-1
DOI :
10.1109/PIMRC.1995.480913
