| 摘要 |
Emergency Location Transceivers (ELT) and communication transceivers (transmitters and receivers) for reception and demodulation of location finder signals, Global Positioning System (GPS) satellite signals and non GPS satellite location finder and other location finder signals. The received location finder signals are demodulated to location finder baseband signals. Baseband signal processors for processing single or a plurality of input signals for providing Orthogonal Frequency Division Multiplex (OFDM) baseband signals, filtered signals, cross-correlated shaped in-phase and quadrature-phase baseband signals and spread spectrum signals. Signal modulators for modulating the processed signals and for providing the modulated signals to the signal transmitter for transmission of the modulated signals. Emergency receiver systems for reception, demodulation and processing of the modulated transmitted signals. Certain emergency receiver embodiments, such as receivers of calls made to emergency call number 911 contain two or more receive antennas for reception and processing of the transmitted modulated signal. In certain embodiments emergency receiver systems have two or more receive antennas operated in a diversity mode, for reception and processing of the transmitted modulated signal. |
