| 摘要 |
<p>A low power, multi-cellular, broadband communication system for the unidirectional (i.e. broadcast), bi-directional and multi-directional transmission and reception of voice, video, audio, television and data signals is provided within the context of a point to multipoint network topology. The system incorporates modem, modulator and demodulator elements that operate over the complete licensed band of the operator. In addition, the microwave transmitter, receiver and transceiver elements also operate over the licensed band of the operator, thereby achieving a broadband microwave infrastructure coupled with a flexible modem (modulator, demodulator) architecture that allows flexible channelization at the systems level. The system may operate over two or more separate frequency allocations, such as a downstream frequency allocation at 24 GHz coupled with an upstream frequency allocation at 36 GHz. This is possible because the partition of cell-site receiving and transmitting functions and the use of subscriber antennas that do not have equivalent transmitter/receiver patterns. This allows for different numbers and different types of receiver or transmitter cell-sites to be implemented. The use of advanced subscriber antenna technology allows for primary and secondary cell-sites to be defined for specific subscribers, thus providing route diversity to combat rain attenuation and rain outage effects, which are the primary cause of outage within the large-area networks operating at frequencies above 10 GHz. The unique system design discussed below allows for route diversity to combat rain and multipath fading effects.</p> |
