Abstract: A remodulator timing signal (35) is generated by a phase locked loop (33) which is coupled to a broadcast vestigial sideband signal (5). Within the signal (5) is highly accurate timing data which is coupled to a demodulator (31). Timing signals to the demodulator are provided by a variable frequency oscillator (32) which receives a correction signal from a phase locked loop (33) housed within the demodulator. The phase locked loop generates the correction signal by comparing the VFO output frequency (36) with the timing data embedded within the broadcast signal (5). A value register (203,303,403) maintains the recent average VFO frequency. A multiplexer (204,304,404) selects the value register data to control the VFO (32,220,320) in the absence of the broadcast timing data.

Abstract: A wireless telephone system comprises a base unit and a plurality of wireless handsets. The base unit has a base transceiver and a memory for storing stored information. Each handset has a handset transceiver for establishing a data link and an audio link with the base unit via the base transceiver, wherein the data link is for transmitting signaling information and the audio link is for transmitting voice data for a real-time telephone call. The handset requests from the base unit certain stored information. In response, the base unit retrieves the requested stored information from the memory and transmits the stored information to the handset via the audio link.

Abstract: In a digital broadcast communications system, a higher priority component and a lower priority component are broadcast from a transmitter to a receiver. Each of these components generates a main and a supplemental signal, and each supplemental signal is advanced in time with respect to the corresponding main signal. The main and supplemental signals for both the higher and lower priority components are combined into a single signal, which is broadcast to a receiver. In the receiver, the time advanced supplemental signals are stored in a buffer to time align them with their corresponding main signals. Both main signals are processed in the normal manner in the receiver, and are also monitored to detect a fading event. When a fading event is detected, the corresponding buffered supplemental signals are substituted for the faded main signals and normal processing continues.

Abstract: A remodulator system includes a source of an input transport packet stream and an input packet buffer coupled to the input transport packet stream source. The input packet buffer generates a status signal indicating whether it is: full, empty, or neither empty nor full. An output packet stream generator is coupled to the input packet stream buffer and responsive to an output clock signal, and generates the output packet stream in synchronism with the output clock signal. A variable output clock signal generator generates the output clock signal responsive to a control signal, and a control signal generator generates the control signal in response to the status signal.

Abstract: A wireless telephone system comprises a base unit coupleable to one or more external telephone lines and having a base transceiver, and a plurality of wireless handsets which may be active or inactive. Each handset has a handset transceiver for establishing a time-division multiple access (TDMA) link, when said handset is active, over a shared RF channel with the base unit via the base transceiver. In communicating via a TDMA link, each active handset communicates during an exclusive time slice of a TDMA scheme that allocates time slices to active handsets, wherein a number of data samples having a sample size are transmitted during each time slice. At least two handsets alternatingly share a time slice, when one of said two handsets is to establish a new TDMA link and when establishing said new TDMA link would exceed the available channel capacity. Time slices are shared by reducing the sample size and thereby increasing the number of data samples transmitted during said shared time slices.

Abstract: A wireless telephone system, having one or more wireless handsets and a base unit. Each handset has a handset transceiver, and the base unit has a base transceiver and a handset docking station, which has a wired interface. The base unit digitally communicates over an RF channel with a handset via its handset transceiver only if the handset has previously been initialized by the base unit. The handset is initialized via the wired interface when it is physically docked in the docking station.

Abstract: An adaptive channel equalizer (50) for processing a demodulated VSB signal containing terrestrial broadcast high definition television information includes an adaptive feed forward filter (FFF 20) and an adaptive decision feedback filter (DFF 30). The equalizer is preceded by a demodulator/carrier recovery network (18) and does not include a carrier recovery function in the equalizer control loop. The equalizer FFF and DFF elements operate adaptively in blind, training, and decision-directed modes. A direct connection provided from the equalizer output to the DFF facilitates coarse signal acquisition and equalization during the blind operating mode.

Abstract: The ATSC standard for digital television broadcast specifies a data Channel in addition to the normal audio and video channels. A methodology is provided for using the ATSC data Channel to broadcast MPEG-4 video streams, for which a new video service is created. The MPEG-4 streams can be encapsulated into MPEG-2 PES (Packetized Elementary Streams) packets or directly into MPEG-2 transport packets. These mechanisms enable the synchronous broadcast of MPEG-4 streams for an ATSC digital TV system without a change to the ATSC standard when data casting.

Abstract: A digital device, such as a digital VTR, receives and records an MPEG compatible datastream. On play back, the DVTR inserts packetized auxiliary information, such as on-screen display information, into the transport datastream for transmission to another digital device, such as a television receiver. Time stamps in the MPEG compatible datastream are unaffected by the insertion of the auxiliary information. The DVTR VSB modulates the datastream to provide sufficient bandwidth for the auxiliary information in the datastream.

Abstract: A wireless telephone system comprises a base unit having a base transceiver, and one or more wireless handsets, each handset comprising a handset transceiver. Each handset establishing a time-division multiple access (TDMA) link over a shared RF channel with the base unit via the base transceiver in accordance with a TDMA epoch, which allocates exclusive data and audio packet time slots to each handset. Each handset powers on its transceiver during its respective data and audio packet time slots as necessary to synchronize with the base unit using synchronization data transmitted with a data packet, to detect incoming call data transmitted with a data packet, or to transmit and receive audio information over the TDMA link. The handset powers off its transceiver otherwise during the epoch to minimize handset power use.

Abstract: In a digital broadcast communications system, a higher priority component and a lower priority component are broadcast from a transmitter to a receiver. Each of these components generates a main and a supplemental signal, and each supplemental signal is advanced in time with respect to the corresponding main signal. The main and supplemental signals for both the higher and lower priority components are combined into a single signal, which is broadcast to a receiver. In the receiver, the time advanced supplemental signals are stored in a buffer to time align them with their corresponding main signals. Both main signals are processed in the normal manner in the receiver, and are also monitored to detect a fading event. When a fading event is detected, the corresponding buffered supplemental signals are substituted for the faded main signals and normal processing continues.

Abstract: A method and apparatus for detecting the presence of a wireless local area network (WLAN) (104) detects at least one signature sequence in a radio frequency (RF) signal associated with a WLAN (104). The present invention indicates the presence of a WLAN (104) in response to the detection of the at least one signature sequence in the RF signal.

Abstract: An output packet stream generator in a remodulator system includes a source of a stream of input transport packets and a source of additional packets. A multiplexer is coupled to the input transport packet stream source and the additional packet source and generates the output packet stream. A control signal has a variable characteristic having a first state when an input transport packet should be inserted into the output packet stream and a second state when additional packets should be inserted into the output packet stream. A multiplexer controller conditions the multiplexer to insert an input transport packet into the output packet stream when the control signal has the first state, and an additional packet into the output packet stream when the control signal has the second state.

Abstract: A method and apparatus for detecting the presence of a wireless local area network (WLAN) (104) determines a position of a mobile device (110) using a position location system (114), receives a position of a WLAN (104) from a location database(112), and determines whether the mobile device (110) is within a service area (108) of the WLAN (104) in response to the position of the mobile device (110) and the position of the WLAN (104).

Abstract: A method and apparatus for detecting the presence of a wireless local area network (WLAN) (104) detects at least one signature sequence in a radio frequency (RF) signal associated with a WLAN (104). The present invention indicates the presence of a WLAN (104) in response to the detection of the at least one signature sequence in the RF signal.

Abstract: An apparatus and method for automatic gain control in spread-spectrum communications includes an automatic gain control apparatus for a spread-spectrum receiver, including a received signal strength indicator, an analog amplifier in signal communication with the received signal strength indicator, an analog-to-digital converter in signal communication with the analog amplifier, a digital automatic gain control loop in signal communication with the analog-to-digital converter, and a digital-to-analog converter in signal communication with the digital automatic gain control loop for providing a signal indicative of a digital gain to the analog amplifier; where the corresponding method for automatic gain control in spread-spectrum communications includes receiving an analog signal, measuring the strength of the received analog signal, deriving a first analog gain in correspondence with the measured strength, applying the derived first analog gain to an analog amplifier, deriving a second analog gain from a pilot

Abstract: A wireless telephone system comprises one or more wireless handsets and a base unit. Each handset has a handset transceiver and a rechargeable handset battery for powering the handset. The base unit has a base transceiver for communicating over an RF channel with each handset via its handset transceiver; a recharge cradle for physically docking a docked handset battery comprising one of a detached handset battery and a handset; and a recharge unit for recharging the docked handset battery. The base unit is coupled to an AC power supply and utilizes the docked handset battery as a backup power supply if AC power from the AC power supply is lost or irregular to prevent communication between the base unit and the handsets from being disrupted.

Abstract: A wireless telephone system comprises a base transceiver having a base receiver and a plurality of wireless handsets. Each handset comprises a handset transceiver for establishing a time-division multiple access (TDMA) link over a shared channel with the base unit via the base transceiver, in which each handset communicates during an exclusive time slot of a TDMA scheme that allocates time slots to handsets. The base receiver is characterized by a plurality of demodulation parameters and is for synchronizing with each handsets. The base receiver stores a set of demodulation parameters for each handset and switches to the set of demodulation parameters for a particular handset when the base unit is to synchronize with the particular handset.

Abstract: A method and apparatus for responding to an incoming call on one of a plurality of external telephone lines when a conference call is in progress on that external telephone line includes the following. First, caller identification information is received relating to the incoming call. Then the plurality of handsets involved in the conference call are notified that an incoming call has been received. Should it be desired to answer that incoming telephone call via a callback, a pre-recorded message is transmitted to the caller of the incoming call requesting the caller hang up and the incoming telephone call is terminated. The caller of the incoming call is then called back on a unused external telephone line using the previously received caller identification information relating to that incoming call. Finally, one of the plurality of handsets involved in the conference call is connected to the caller of the incoming call.

Abstract: A method and apparatus for detecting the presence of a wireless local area network (WLAN) (104) detects at least one energy fluctuation in a radio frequency (RF) signal propagating in a WLAN frequency band and indicates the presence of a WLAN (104) in response to the detection of the at least one energy fluctuation.