Ultra narrow band and ultra wide band modulation compared

Ultra Wide Band and Ultra Narrow Band modulation can be shown to be mathematically related methods, but with widely different characteristics. In some variations, they are both ON/OFF amplitude pulse position methods. UWB is mostly OFF, while UNB is ON for most of the bit period. UWB generates a large number of sidebands that must be to detect the signal. Some sources say it has no carrier. UNB; has a strong CW carrier and removes the sidebands with ultra narrow band filters, since they are of no value to the detected signal. UWB requires a very broad noise bandwidth. UNB transmits only a single frequency, hence has a very narrow noise bandwidth. The same mathematical formulas apply to both in the spectral analysis.