1-3hit |
A dual-polarized multimode CDMA based local multipoint distribution system (LMDS) is presented. The twisted sector concept and narrowed sector cell are proposed to improve the system performance. Inter-cell interference is analyzed and discussed for the downstream direction based on hexagonal cell architecture. The bit error rate (BER) performance of a multimode CDMA scheme is investigated in terms of the worst case for high order modulation. The simulation results show that the proposed cell structure obtains better power efficiency and makes the multimode CDMA scheme feasible in LMDS deployment.
This paper investigates an obstructed radio channel by foliage for LMDS (local multipoint distribution services) where a relative evaluation of attenuation characteristics of foliage at 29.5 and 5 GHz is performed. Results show that the attenuation in dB should be treated statistically as Rician distribution. It is also found that swaying foliage in wind causes a significant channel fading at 29.5 GHz, ranging over 10 dB, while the fading depth at 5 GHz is approximately 2 dB.
Ichihiko TOYODA Makoto HIRANO Masami TOKUMITSU Yuhki IMAI Kenjiro NISHIKAWA Kenji KAMOGAWA Suehiro SUGITANI
A procedure for quickly developing highly integrated multifunctional MMICs by using the three-dimensional masterslice MMIC technology has been developed. The structures and advanced features of this technology, such as miniature transmission lines, a broadside coupler, and miniature function block circuits, enable multifunctional MMICs to be quickly and easily developed. These unique features and basic concept of the masterslice technology are discussed and reviewed to examine the advantages of this technology. As an example of quick MMIC development, an amplifier, a mixer, and a down-converter are fabricated on a newly designed master array.