摘要:
A time-framed communications transceiver maintains synchronization through fade conditions by resetting a counter (640) whenever new synchronization parameters are stored in a memory (630) based on bursts detected by a receiver (610) and a burst synchronizer (620). A transmitter (690) transmits bursts based upon the synchronization parameters in the memory (630) when the time counter (640) has not exceeded a predetermined period of time. The receiver (610) re-establishes the synchronization parameters in the memory (630) when the time counter exceeds another, longer predetermined period of time before transmission by the transmitter (690).
摘要:
A paging repeater (22) receives (152) a paging signal (30) transmitted (138) by a low-earth orbit satellite (24) while compensating (150) for Doppler effects, modifying (156) the paging signal (30) to produce a repeat signal (40), and transmitting (166) the repeat signal shifted in both the time and frequency domains so as to preclude the generation of interference. A pager (28) receives a paging signal (30) directly from the satellite (24) while compensating (108) for Doppler effects whenever the pager (28) is unshadowed with regard to the satellite (24), or receiving a repeat signal (40) from a paging repeater (22) whenever the pager (28) is shadowed with regard to the satellite (24).
摘要:
A method for a radio frequency communication unit (110) (CU) to hand off from a losing node (120) to a gaining node (122) estimates a gaining node uplink time (210) and a gaining node uplink frequency (212), which the gaining node uplink signal comprises. During handoff, the CU (110) ceases communications with the losing node (120) and immediately begins communications with the gaining node (122) using the uplink time and uplink frequency. A CU apparatus (300) uses a processor (302) for carrying out calculations necessary for estimating the gaining node uplink time and frequency. Information necessary for the calculations, such as a downlink signal time-of-arrival and Doppler offset, are collected by a CU receiver (306). The CU receiver (306) and a CU transmitter (304) are used to support downlink signals (142) and uplink signals (140), respectively, between the CU (110) and a node (120, 122).
摘要:
In a telecommunication system (15) with at least one gateway (1), subscriber units (2), system controller (3), at least one communication satellite (4) and global positioning satellites (5), gateway (1) provides a global positioning data service to subscriber units (2). Gateway (1) receives ephemeris and almanac data on link (7) from global positioning satellites (5). Requests for portions of the data are received via link (11) and these portions are transmitted on link (10). Subscriber unit (2) receives on link (6) positioning information which is used by subscriber unit controller (33) to self-determine accurate location data. Subscriber unit (2) transmits a global positioning data service request via link (8) and receives the requested global positioning data service data via link (9).
摘要:
A radome (310) made of a cylindrical tube sealed on a first end and open on a second end houses a multiple-arm antenna element (405). The radome is formed with at least two grooves (340, 350) on an inner surface of the cylindrical tube for meshing with arms (410, 420, 430, 440) of the multiple-arm antenna element (405).
摘要:
A cellular telephone (110) forms part of a wireless communication system (100) and has simultaneous communication of radio and cellular signals. The wireless communication system (100) has a base station (115) and one or more radios (120). The cellular telephone (110) has control circuitry (205), a cellular transceiver (215), a radio transceiver (210), a microphone (220), and a speaker (225). The simultaneous communication of radio and cellular signals permits a radio user to participate in a cellular phone call and permits a cellular telephone user to participate in the radio communication. Simultaneous communication is communication of cellular and radio signals at the same time and at substantially the same time.
摘要:
A satellite communication system provides users with global cellular coverage. To facilitate delivery of calls to users having subscriber units, a fixed channel is defined wherein subscriber units are notified of incoming calls. Subscriber units monitor this ring alert channel and examine subscriber unit IDs transmitted in a ring alert message contained therein. When a subscriber unit determines from the subscriber unit ID that a call is being directed to it, it calls into a network to receive a call. Subscriber units also monitor this fixed channel to receive a control channel directory identifying the location of a subscriber unit's broadcast (control) channels.
摘要:
An amplifier circuit (100) includes a power amplifier (124) that has a modulated power supply input (125). The modulated power supply input (125) is modulated with a signal related to the amplitude of the signal being amplified by the power amplifier (124). The power amplifier (124) is maintained at a substantially constant operating point. The amplifier circuit (100) also includes a feedback path that generates an error signal as a function of the input signal envelope and the output signal envelope. The error signal is integrated and the resulting integrated error signal drives the gain control of a variable gain element (120) in the amplifier chain prior to the power amplifier (124).
摘要:
In a telecommunication system (15) with at least one gateway (1), at least one subscriber unit (2), a system controller (3), at least one communication satellite (4) and global positioning satellites (5), communication satellite (4) provides positioning information to subscriber units (2). System controller (3) uses links (13,14) with communication satellites (4) to control links (10,11) and links (8,9). Subscriber unit (2) receives on link (6) positioning information which is used by subscriber unit (2) to determine which global positioning satellites (5) are overhead. Knowing which global positioning satellites (5) are overhead allows subscriber unit (2) to more quickly acquire and track the global positioning satellites (5) required to accurately geo-locate itself. Subscriber unit (2) computes accurate location data and can transmit this data to gateway (1).