Abstract:
A communication system implements a method of bidirectional communication of signals to/from one or more wireless transmit locations. Transmitting signals to one or more wireless transmit locations includes obtaining a plurality of signals having different protocols, from a plurality of base stations, then converting the plurality of signals into common digital network protocol signals, and transmitting the common protocol signals over a transmission network to one or more wireless transmit locations. Receiving signals from one or more wireless transmit locations includes transmitting digital signals using a common protocol, from one or more wireless receive locations over the transmission network, converting the received digital signals into a plurality of signals having different protocols corresponding to a plurality of base stations implementing said different protocols, and providing the plurality of differing protocol signals to said corresponding plurality of base stations.
Abstract:
A delay mismatched feed forward power amplifier is disclosed. Loop 1 includes a main amplifier and is used to derive a carrier cancelled sample of the main amplifier output. Loop 2 includes an error amplifier used to amplify the carrier cancelled signal derived from Loop 1 operation in order to cancel distortion products generated due to the nonlinear nature of the main amplifier. Loop 2 also utilizes a very short Loop 2 delay line. A significant efficiency gain is provided due to reduced output power losses associated with the Loop 2 delay line. Lower output losses also results in lower distortion levels produced by the main amplifier. This, in turn, reduces the size and performance requirements placed on the error amplifier. A smaller and more efficient error amplifier is employed resulting in further amplifier system efficiency improvement. The delay mismatch is compensated by a third control loop, a special adaptive control algorithm or a combination thereof.
Abstract:
A system and method for distributing multiple wireless carriers to transmission sites is disclosed. Carrier precursors are distributed which are digital in format and compressed in bandwidth. The individual carrier precursors are combined using time division multiplexing to eliminate the need for excess bandwidth allotments. A separate time division multiplexed control channel is created to communicate carrier configuration and operating status information. With the carrier precursor data and configuration information, a software-defined radio is used to create actual carriers at or near the transmission location. Creating carriers at or near the transmission location provides the additional benefit of reducing transmission losses between the transmit antenna and the signal generating radio.
Abstract:
The present invention provides a remote antenna system employing digital imaging means by which the operator can view both the antenna pointing data and the coverage landscape from the antenna radome perspective. The present invention also provides a method for antenna positioning data acquisition and positioning control employing remotely acquired image data.
Abstract:
A predistortion linearized amplifier system that uses analog polynomial based predistortion is disclosed. An analog polynomial function generator receives polynomial parameter updates from a polynomial parameter generator. The polynomial parameter generator uses a combination of analog and digital signal processing to create the parameter updates. This processing is performed on input signal amplitude, detected using analog circuits, and RF coupled samples of the input signal, and the output signal. By using a combination of analog and digital signal processing means, digital processing can be performed at sub-Nyquist rates, significantly reducing the cost of digital circuits. Also, since the predistortion modulation signal is created with an analog function generator, time correlating delay is minimized reducing circuit costs.
Abstract:
A system and method for providing a peak power reduced OFDM communications signal are disclosed. The system and method provide peak reduction processing in the time domain followed by inter-symbol interference (ISI) control processing in the frequency domain to maintain modulation errors introduced by the peak reduction processing to an acceptable level. The processing is preferably done on a parallel signal path and the peak corrections with ISI control are added into the main signal path to provide the peak reduced OFDM signal.
Abstract:
The present invention provides a remote antenna system employing digital imaging means by which the operator can view both the antenna pointing data and the coverage landscape from the antenna radome perspective. The present invention also provides a method for antenna positioning data acquisition and positioning control employing remotely acquired image data.
Abstract:
A feed forward amplifier and method of amplification are disclosed. The amplifier output is used to generate a pilot signal via feedback using uncancelled noise in the amplifier output. An automatic level control circuit maintains the pilot signal at a substantially constant level when the detected uncancelled noise in the amplifier output is above a threshold level. The generated pilot signal strength is allowed to vary when the detected uncancelled noise in the amplifier output is below the threshold and disappears automatically when the amplifier is aligned.
Abstract:
A delay mismatched feed forward amplifier system employing a control system and method using floors and penalties is disclosed. The disclosed control system and method allows the second loop phase adjuster setting to be offset in a repeatable and controlled manner. Applying floors and penalties to offset the steady-state phase adjuster setting modifies the conventional pilot cancellation approach. In the conventional case, pilot cancellation has a distinct minimum that corresponds to the desired adjustment setting. In the disclosed approach, the measured pilot cancellation is clipped to a lower bound or floor to produce a set of equal valued minimum control results. The floor is selected to place a desired phase offset to the phase adjuster at the edge of minimum floor. To ensure that the correct phase adjuster offset is selected from the set of equal valued minimum control results, a control direction based penalty is added. By including both the floor and penalty, the phase adjuster steady state offset will be controlled to the edge of the minimum floor.