Title :
A new 32QAM modem for doubling transmission capacity in 40 MHz channelling plans
Author :
Balducci, P. ; Bolla, M. ; Rossi, L. ; Spalvieri, A.
Author_Institution :
Alcatel-Telettra, Vimercate, Italy
Abstract :
Frequency reuse enables one to double spectrum efficiency of radio systems. This technique is of great interest for microwave bands below 10 GHz, which are now fully occupied by conventional interleaved channels. The first step is frequency reuse of 40-MHz channel arrangements, which typically use 16 quadrature amplitude modulated (QAM). 140-Mb/s systems. A 32QAM system equipped with a baseband cross polarization interference canceller (XPIC) which may be used with the same structures of the installed 16QAM radios with no loss in performance is proposed. Future 32QAM modulation will also be possible for synchronous STM1 155.52-Mb/s signals. The hardware implementation of a 32QAM modem, including measurement results, is presented
Keywords :
amplitude modulation; digital radio systems; microwave links; modems; 10 GHz; 32QAM modem; 32QAM system; 40 MHz; SHF; baseband cross polarization interference canceller; frequency reuse; interleaved channels; measurement results; microwave bands; radio systems; spectrum efficiency; synchronous STM1; transmission capacity; Amplitude modulation; Baseband; Frequency; Hardware; Interference cancellation; Microwave bands; Modems; Performance loss; Polarization; Quadrature amplitude modulation;
Conference_Titel :
Global Telecommunications Conference, 1992. Conference Record., GLOBECOM '92. Communication for Global Users., IEEE
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-0608-2
DOI :
10.1109/GLOCOM.1992.276701
