Flexible impulse radio spectrum control in terms of a specific class of time hopping codes

The paper proposes a specific class of time hopping codes which are generated easily and can be used to control the power spectral density of ultra wideband time hopping impulse radio. A closed form expression is derived for the power spectral density of impulse radio with binary pulse amplitude modulation and this class of time hopping codes, based on which the influence of signal parameters on the power spectral density is analyzed, and signal parameter design guides are presented to suppress the power spectral density in designated frequency bands below a prescribed extent. Simulations demonstrate the analysis.