Abstract:
Methods and systems are provided for spreading spectral density of pulse streams during digital to analog conversion. An example spreading circuit may comprise an accumulator circuit, a bit generator circuit, a comparator circuit, and an inverter circuit. The accumulator circuit may be operable to receive a signal to be spread and generate an output based on the signal to be spread and at least one other input. The bit generator circuit may be operable to input into the accumulator circuit zero-sum sequences. The comparator circuit may be operable to provide a stream of pulses based on the output of the accumulator circuit. The inverter circuit may be operable to invert output of the comparator circuit, wherein output of the inverter circuit is input into the accumulator circuit.
Abstract:
A spreading method and apparatus for spreading the spectral density of a pulse stream by summing a set of randomly selected zero-sum sequences to an incoming pulse stream and ensuring that the number of pulses output by the spreading method and apparatus is equal to the number of pulses input to the spreading method and apparatus.
Abstract:
An ultra-wideband communication and/or location system having a plurality of channels, each implementing a respective one of a plurality of predetermined codewords. Within each channel, one or more predetermined pulse repetition frequences are defined. Within a single UWB system, more than two networks of transceivers may be co-located without mutual interference if each is assigned a unique combination of codewords and spreading factors.