摘要:
The present invention is a system and method for automated position location using RF signposting. The present invention comprises a plurality of transmitting units placed throughout a service area. Each transmitting unit repeatedly transmits a signal including position information related to a position associated with the transmitting unit. The position information may be an absolute position or an encoded position based on the structure of a building in which the transmitting unit is located. A receiving unit receives the signal transmitted from a transmitting unit and determines the position of the receiving unit, based on the received indication. The transmitting units are placed to provide uniform coverage of the service area, thus providing position location indoors and in urban areas where GPS does not function properly.
摘要:
In an example embodiment of the present invention, the method includes creating a plurality of data packets. Each data packet in the plurality of data packets includes a plurality of coded cellular signals. The plurality of data packets are sent over a data network associated with at least one sector served by a plurality of transceivers, and at least one of the plurality of transceivers broadcasts the data packets. A location of a mobile station is determined based on received multi-paths associated with response from the mobile station to broadcast of at least one of the plurality of data packets.
摘要:
A time-division-multiplexed fixed wireless loop system and methods therefor are disclosed. The system comprises a plurality of cells each having a base station and a plurality of terminals. The base station includes a steerable and adjustable multibeam antenna for communicating with each of the terminals, which have fixed antennas. A cell controller associated with each base station allocates communication time slots so as to minimize mutual interference between base station/terminal links sharing the same time slot. Slot assignment is based on regional, periodically updated interference measurements that are stored in data bases.
摘要:
A method for combining digital data with a perceptible program signal. The data stream is modulated onto an electromagnetic signal encoding the perceptible signal; the modulating employs a spread spectrum encoding of the data stream. The modulated program signal is transduced into perceptible form. A capture device receives the perceptible signal, and a decoder extracts the spread spectrum encoded data from the received signal. The method is particularly useful in encoding purchase information or watermarking information into the signal.
摘要:
An system and apparatus records and displays information received from a premises such as ambient temperature or information received over a telephone network. A premises recording unit is connected to a telephone network and receives and stores telephone information received therefrom. The premises recording unit includes a wireless transmitter for generating and transmitting a packet of telephone information received from the telephone network. The generated signals can be radio, infrared and ultrasonic. A packet receiver is spaced distant from the premises recording unit but within range of the packet transmission generated therefrom for receiving and storing the packet of telephone information. The packet receiver displays at least a portion of the packet of information.
摘要:
A wireless Local Area Network (LAN) includes a repeater which a) synchronizes interface adapters for portable end-user devices and b) retransmits data signals received which retimes and retransmits data signals received from these end-user devices that gain, one at a time, the exclusive right to transmit those signals during a given transmission time subframe by contending for access to the LAN resources that are auctioned off to permit LAN resource utilization that is independent of traffic load and that is implemented in a near collision-free environment.
摘要:
Digital information is encoded in the video portion of a television signal such that "n" (n is an integer) bits of the digital information are carried by each successive frame in a group of frames. The digital information is encoded by modulating a carrier signal, using, for example, either amplitude shift keying (ASK) or frequency shift keying (FSK), and the modulated carrier is then added to the video signal selectively, only in portions of the television program that (a) are not likely to be perceptible by a viewer, and (b) are of sufficient intensity to transmit the data. The video signal including the encoded digital data, may be transmitted, in real time, to a television receiver, or recorded for later playback. In either event, at a receiver, when the video signal containing the encoded information is displayed on a screen, the image is sensed or "viewed" by a photo detector, the output of which is applied to a band pass filter having a center frequency that corresponds to the oscillator frequency(s) in the encoder. The filter output is thresholded or FM detected, so that the receiver can recover the encoded data. By appropriately including checks bits and synchronization patterns, the bit stream output from the decoder can be synchronized, and the original encoded data recovered. Advantageously, the frequency of the oscillator in the ASK or FSK encoder is chosen so that the energy added to the video signal is in a portion of the frequency spectrum that otherwise contains little energy. This makes the added digital data imperceptible to a viewer. If desired, the same data may be repetitively encoded in several groups of frames, so as to increase the redundancy and thus the reliability of the overall system.
摘要:
Cellular signals or other wireless signals/messages are introduced into a building or to an outside location by transmitting packets corresponding to those signals over a data network and low cost cables to designated locations within the data network. Once the designated packets containing the signals reach the destination, they are then broadcast over the air to a terminal capable of receiving the wireless message. In a first embodiment, an in-building gigabit Ethernet network, such as that currently existing presently in many buildings, is used to distribute radio signals indoors. Instead of transmitting the radio signals over the air from a repeater connected to a base station, coded baseband signals generated by the coding processor (e.g., a CDMA Modem Unit) in the base station are packetized and sent over the Ethernet network to radio processing equipment and antennas distributed throughout the building. The radio processing equipment strips the packet headers from the baseband signal packets so those signals can be broadcast via the antennas to one or more mobile terminals.
摘要:
A plurality of carrier signals in a wide band signal is converted into a plurality of digital carrier signals. Each of the plurality of carrier signals is at a respective frequency in the wide band signal. At least one of the plurality of digital carrier signals is translated to a different frequency.