摘要:
A system is provided for transmitting data to a plurality of devices. A data source receives data from a video broadcasting source, such as a digital television provides, through a data cable. The data source identifies devices to receive particular sets of data, such as particular programs, from the data cable. The data source identifies particular settings for transmitting to particular devices. The data source adjusts a transmission power to a first device to efficiently provide data reliably to the first device. The data source can assign more or less power for transmitting data to the first device. The data source provides data to the source device using a first data channel. The data source provides data to a second device using a second data channel. The data source receives acknowledgements and control information from the first device and the second device using the second data channel.
摘要:
A method and apparatus for synchronized channel transmission are disclosed. One embodiment of the method comprises: generating a first data stream and a second data stream; packetizing the first data stream to produce a first plurality of data packets; packetizing the second data stream to produce a second plurality of data packets; baseband processing the first plurality of data packets to produce a first plurality of symbols for each of the first plurality of data packets; baseband processing the second plurality of data packets to produce a second plurality of symbols for each of the second plurality of data packets; converting the first plurality of symbols into a first radio frequency signal; converting the second plurality of symbols into a second radio frequency signal; and synchronizing at least one of: generating the first and the second data streams, packetizing the first and second data streams, baseband processing the first and second plurality of data packets, and converting the first and second plurality of symbols.
摘要:
An ADSL receiver (200) receives an upstream modified ADSL signal and an ISDN signal from a remote terminal (32) on a twisted-pair copper wire (18). An ADSL transmitter (100) of the remote terminal (32) transmits the ADSL signal in a frequency range above an ISDN frequency range so that the ADSL signal does not overlap the frequency range of the ISDN signal. In one embodiment, the ADSL receiver (200) includes a band pass filter (201), an analog-to-digital converter (203), a decimator (205), a fast Fourier transform (210), and a digital signal processor (212). The decimator (205) converts the ADSL signal back to base band, thus allowing an ADSL signal source to simultaneously utilize the telephone line with an ISDN signal source, without significantly reducing ADSL throughput.
摘要:
A transceiver (5) for an asymmetric communication system such as asymmetric digital subscriber line (ADSL) includes a configuration register (71) defining operation at either a central office (CO) or a remote terminal (RT). The configuration register (71) includes a control bit (72) for selecting either CO or RT mode. The transceiver (5) includes a signal processing module (70) configured according to the state of the control bit (72). For example, a digital interface (70) converts transmit data into transmit symbols and converts received symbols into receive data. The digital interface (70) uses a large memory (158) as a buffer in the transmit path and a small memory (160) as a buffer in the receive path in CO mode. In RT mode, the digital interface (70) uses the small memory (160) in the transmit path and the large memory (158) in the receive path. The selective configuration allows a single integrated circuit to be used in both CO and RT equipment.
摘要:
A flexible asymmetrical digital subscriber line (ADSL) transmitter is able to operate simultaneously with integrated services digital network (ISDN) terminal equipment (TE) using a common telephone line (18). The ADSL transmitter changes the frequency content of a frequency-encoded ADSL signal (104) so that its frequency content does not overlap the frequency content of the ISDN TE signal. A corresponding ADSL receiver located within a central office (CO) adapts to the changed frequency content, allowing the ADSL signal to be transmitted over the telephone line without substantial loss of signal integrity. In one embodiment, an ADSL transmitter (100) converts ADSL symbols making up the frequency-encoded ADSL signal (104) into a corresponding time domain signal. The transmitter (100) then interpolates the time domain signal and high pass filters the interpolated signal. This high pass filtered signal is then converted to analog form, bandpass filtered, and driven onto the telephone line (18).
摘要:
In one embodiment, a method includes receiving and processing an incoming radio frequency (RF) signal in a receiver. Based on this signal, an environmental noise level can be determined, where this level corresponds to environmental noise present in an environment in which the receiver is located. Then, if the environmental noise level is substantially greater than receiver-generated noise, power consumption of at least one analog front end component of the receiver can be reduced.
摘要:
Systems and methods for controlling operation of an integrated circuit by applying below ground voltage to one or more pins of the integrated circuit, and in which the application of a below ground pin voltage may be employed as an initiator of (or condition for) a given mode of circuit operation in a manner that prevents the inadvertent initiation of the given mode of operation that may otherwise occur due to accidental application of an above ground voltage to one or more pins of the integrated circuit.
摘要:
A method for mitigating interference from a switched-mode power supply begins by comparing a channel of interest of a plurality of channels with a switching rate of a switch-mode power supply. The method continues when the channel of interest compares unfavorably to the switching rate by adjusting the switching rate of the switch-mode power supply until the channel of interest compares favorably to the switching rate.
摘要:
A system on a chip integrated circuit includes a first in-phase digital submodule and a first quadrature phase digital submodule such that the first in-phase digital submodule and the first quadrature phase digital submodule are operable to produce at least one output signal based on at least one input signal. A digital clock generator generates a first in-phase digital clock signal having a plurality of first in-phase digital clock cycles over a predetermined period and a first quadrature phase digital clock signal having a plurality of first quadrature phase digital clock cycles over the predetermined period. The plurality of first in-phase digital clock cycles are substantially interleaved with the plurality of first quadrature phase digital clock cycles over the predetermined period.
摘要:
A digital clock generator includes a base clock generator for generating a base clock signal at a variable base clock frequency in response to a control signal. A digital clock controller generates a digital clock signal having a substantially constant number of digital clock cycles over a predetermined period.