Patent ID: 7187715

Claim:
A method of modulating a communications signal within an ultra-wideband (UWB) communications system, comprising: receiving a plurality of bits in an input data stream; receiving at least one spreading code sequence comprising a plurality of code elements having either a first value or a second value; encoding each bit of the stream of input data bits into a symbol having a finite symbol period, and comprising a plurality of chips, wherein each chip has a chip period; associating at least one code element with each chip in the symbol; generating an encoded pulse for each chip of the symbol, wherein each encoded pulse has a value equal to the product of a bit and the code value associated with the particular chip; and modulating the position of the encoded pulse within each chip by placing the pulse at a first position if the encoded value associated with the pulse is a first value and placing the pulse at a second position if the encoded value is a second value, wherein the first position and second position are separated by a time shift equal to one-half of a chip period, the period being greater than a delay spread associated with the Ultra wideband (UWB) communications system.