摘要:
A radio frequency front end for a television band receiver and spectrum sensor includes a first plurality of adaptive matching networks connected to a signal summer that combines signals received by the first plurality of antennas respectively connected to the first plurality of adaptive matching networks and outputs a combined signal to each of a second plurality of downconverter/tuners. The downconverter/tuners are respectively or collectively connected to an analog to digital converter that converts output of the second plurality of downconverter/tuners into at least one digital signal that is output to the television band receiver and spectrum sensor.
摘要:
A radio frequency front end for a television band receiver and spectrum sensor includes a first plurality of adaptive matching networks connected to a signal summer that combines signals received by the first plurality of antennas respectively connected to the first plurality of adaptive matching networks and outputs a combined signal to each of a second plurality of downconverter/tuners. The downconverter/tuners are respectively or collectively connected to an analog to digital converter that converts output of the second plurality of downconverter/tuners into at least one digital signal that is output to the television band receiver and spectrum sensor.
摘要:
This invention discloses directional antenna systems, antenna combining and transmission antenna selection mechanism for wireless communication terminals such mobile handsets, mobile embedded laptops, mobile CPEs (Customer premises equipment), nomadic wireless CPEs, fixed wireless terminals and etc. The disclosed systems and methods only require analog circuitry and compass readings therefore are easy to implement and well fit into the current wireless terminals architectures. The inventive systems and methods resolve the problem that a directional antenna may not receive properly when user turn around and the antenna direction is deviated from transmitter; the inventive systems and methods further reduce the interference caused by omni antenna systems by selecting a directional antenna for transmit.
摘要:
A wireless microphone system broadcasts a pilot tone at the designated ATSC pilot position in the TV Band channel being used by the wireless microphone system. The pilot tone is a readily detectable waveform transmitted in the ATSC pilot position. The pilot tone can be generated by any one of: a standalone pilot tone generator; a pilot tone generator incorporated into a wireless microphone receiver; or, a pilot tone generator incorporated into a wireless microphone.
摘要:
Wireless devices, transmitters, systems and methods are provided that have a narrow band signalling channel and a wide band channel, for example an OFDM channel. In order to save power, the wireless device is nominally powered down with the exception of a receiver specific to the narrow band signalling channel. Once instructed to do so over the narrow band signalling channel, the wireless device wakes up the rest of its wide band receive circuitry.
摘要:
This is invention discloses a perturbation antenna system for wireless communication terminals such mobile handsets, mobile embedded laptops, mobile CPEs (Customer premises equipment), nomadic wireless CPEs, fixed wireless terminals and etc. The perturbation antenna output is analogically combined with that of the primary antenna. The combined result is to re-create the antenna pattern shape and its direction pointing in order to achieve gains by user intercept. A variable delay circuitry is equipped to the perturbation antenna therefore the user's interception can be enforced via programmable apparatus either by manually or by digital inputs. The user can tune the delay parameters meanwhile observe the antenna pattern changes and the call quality until satisfaction.
摘要:
A wireless microphone system broadcasts a pilot tone at the designated ATSC pilot position in the TV Band channel being used by the wireless microphone system. The pilot tone is a readily detectable waveform transmitted in the ATSC pilot position. The pilot tone can be generated by any one of: a standalone pilot tone generator; a pilot tone generator incorporated into a wireless microphone receiver; or, a pilot tone generator incorporated into a wireless microphone.
摘要:
A method for synchronizing network elements to a global clock derived from the GPS clock acquired by a plurality of base stations. The global clock is distributed to controllers of various networks, and from there to network access devices. The network access devices further distribute the global clock to various wire-line and local wireless networks and from there, to the users served by these networks. The user equipment is enabled with a simple clock discipliner that adjusts the local clock to the global clock, resulting in a reliable synchronization across the converged communication networks.
摘要:
A received signal comprises a continuous sequence of symbols φ1, φ2, . . . φn, each represented by a sequence of samples X0, X2, . . . Xn−1, and wherein the symbols have a guard period GP of duration Tgp at the beginning thereof. Each guard period contains a cyclic prefix with the same subsequence of samples as a tail end portion of the associated symbol. The symbols are identified by delaying the received signal by a fixed number of samples, computing the correlation of the received signal with the delayed signal, computing the summation of said correlation over a window of duration Ti, wherein Ti>Tgp, and sliding the window over the correlation to find a characteristic point or region. The start of each symbol for further processing is selected from the characteristic point or region. By increasing the duration of the window, more robust performance can be achieved, especially in multipath conditions.
摘要:
A television band device has DTV pilot signal detection logic that generates DTV pilot signal detection decisions associated with a monitored television channel. A wireless microphone detection logic generates wireless microphone detection decisions associated with the monitored television channel. A sensing manager receives DTV pilot signal detection decisions and the wireless microphone detection decisions and analyzes at least one the respective decisions to determine whether the monitored television channel is available white space.