Abstract:
A method is provided for giving signal quality feedback in a wireless network. First, a transmitting device sends a data packet to a receiving device in a data signal (805). This data signal is sent at a first transmission power and a first data transmission rate. The receiving device receives the data packet in the data signal and determines a signal quality metric for the data signal. The receiving device then sends an acknowledgement frame to the transmitting device in an acknowledgement signal (815). The acknowledgement frame includes one or more feedback bits, which indicates a relative signal quality of the data signal. The transmitting device receives the acknowledgement frame in the acknowledgement signal at the transmitting device, and adjusts the first transmission power and the first data transmission rate to a second transmission power and a second data transmission rate, respectively, based on the one or more feedback bits (835, 840, 845).
Abstract:
A process is provided for determining the distance between two devices by sending ranging packets between them. The local device sends a first ranging packet, which the remote device sends holds for a first hold time before sending a second ranging packet in return. The local device also sends a third ranging packet, which the remote device sends holds for a second hold time before sending a fourth ranging packet in return. If the second hold time is twice the first hold time, then the propagation time for signals between the two devices can be determined solely by time measurements made by the local device. For received signals, these time measurements can be adjusted to provide accurate time estimates for a direct line of sight signal, which corresponds to a shortest transmission distance between the two devices. The propagation time can then be used to determine distance between the devices.
Abstract:
A method is provided for generating a frequency stable wavelet. Initially, a first sine wave is generated having a first frequency. The, a half sine wave window (720) is generated having a window frequency. The first sine wave and the half sine wave window are then mixed (740) to create the frequency stable wavelet. In this process the sine wave has a frequency greater than the half sine wave window so that the half sine wave window covers more than a single sine pulse. The half sine wave window can be created by generating a second sine wave (730) having a second frequency that is twice the window frequency, and then fully rectifying (735) the second sine wave. The wavelets created in this manner can be used for a variety of purposes, including correlating with a received signal or transmitting as a wireless signal.
Abstract:
A mechanism and method are provided for self-canceling noise generated in a UWB receiver and for providing multi-mode operation for the receiver. Noise is canceled by generating a first set of wavelets in a same phase as an incoming signal, and a second set of wavelets with an opposite phase as the incoming signal. The received signal and the generated wavelets are mixed and the result integrated such that the integrated output tends to zero. The multiple modes of operation allow the receiver to process multiple types of waveforms. The modes may be chosen by a user-selected switch, a waveform-detection based switch, or the like.
Abstract:
A mono-cycle generating circuit includes a multiplexer, a pulse generating circuit, and a buffer circuit. The multiplexer receives data of a logical 1 or a logical 0, determines whether to generate a positive mono-cycle or a negative mono-cycle, based upon the data, and outputs clock signals varying in time based upon the data. The pulse generating circuit is coupled to the multiplexer, receives the clock signals and generates a first series of pulses including an up-pulse preceding a down-pulse, or a second series of pulses including a down-pulse preceding an up-pulse, in response to the clock signals received by the multiplexer. The buffer circuit is coupled to the pulse generating circuit and includes a switch circuit and a common mode buffer. The switch circuit generates the positive mono-cycle or the negative mono-cycle, based upon whether the first series of pulses is received from the pulse generating circuit or the second series of pulses is received from the pulse generating circuit. The common mode buffer circuit is coupled to the switching circuit and reduces noise generated by the switch circuit.
Abstract:
A method is provided for generating a frequency stable wavelet. Initially, a first sine wave is generated having a first frequency. Then, a half sine wave window is generated having a window frequency. The first sine wave and the half sine wave window are then mixed to create the frequency stable wavelet. In this process the sine wave has a frequency greater than the half sine wave window so that the half sine wave window covers more than a single sine pulse. The half sine wave window can be created by generating a second sine wave having a second frequency that is twice the window frequency, and then fully rectifying the second sine wave. The wavelets created in this manner can be used for a variety of purposes, including correlating with a received signal or transmitting as a wireless signal.
Abstract:
A method is provided for passing management frames between a network coordinator and a plurality of devices during a plurality of repeating superframes. The superframes are divided into repeating groups of consecutive superframes that form a superframe cycle. Each superframe has a set number of management time slots in it, which number can change. This creates a number of unique management time slots in each superframe cycle based on the number of superframes per cycle and the number of management time slots per superframe. The devices are assigned to a number of contention groups equal to the total number of management time slots in a superframe cycle. Each contention group is assigned a unique management time slot, and each device can only send management requests to the coordinator during the unique management time slot assigned to its contention group. Contention groups may have zero or one device in them.
Abstract:
A receiver correlator structure for an ultra wide bandwidth communication system includes an antenna, a mixer, a bandpass filter, and a convertor. The receiver receives, via the antenna, an ultra wide bandwidth signal comprising a sequence of wavelets of particular shapes and positions, and transmits the received ultra wide bandwidth signal to the mixer. The mixer also receives and mixes with the received ultra wide bandwidth signal a local ultra wide bandwidth signal comprising a sequence of wavelets of particular shapes and positions correlated to the received ultra wide bandwidth signal. The bandpass filter removes the DC components from the mixed signal, and provides the resultant signal to the convertor. The receiver structure eliminates the local ultra wide bandwidth signal AC bias and DC bias terms and 1/f noise, yet detects long sequences of logical 1's and 0's, and allows operation will reduced bandwidth convertors.
Abstract:
A monocycle forming network may include a monocycle generator, up and down pulse generators, data modulators and clock generation circuits. The network may generate monocycle pulses having very narrow pulse widths, approximately 80 picoseconds peak to peak. The monocycles may be modulated to carry data in ultra-wideband communication systems.
Abstract:
A system, method, and computer program product for removing "narrowband" interference from a broader spectrum containing a Ultra Wide Band (UWB) signal, in a receiver of the UWB signal. The Radio Frequency Interference (RFI) is extracted from a broader spectrum to remove interference from the UWB signal, by employing an impulse response in a radio front-end of the UWB receiver that is matched with an incoming wavelet employed as part of a UWB signal to be received, matching the impulse response to the wavelet and its time-shifted and inverted versions, passing the wavelet unscathed through the receiver, and excising narrowband signals (continuous tones). Exemplary embodiments for the RFI extraction mechanism include a transmission line circuit, an active transmission line circuit, and an adaptable, controllable phase delay circuit.