Ultra-wideband impulse radio based on pulse compression technique

The energy transmitted per bit limits the radio coverage. In impulse radio the UWB pulses used carry a very little energy since they are extremely short. As a consequence the radio coverage is unacceptable short. A solution to increase the energy per bit is the enlargement of the duration of UWB carrier pulse, however, this solution cannot be used because the correlation of received pulse envelope with a reference pulse defined in IEEE Std. 802.15.4a has to exceed a prescribed value. This problem can be overcome if the pulse compression approach is used. This technique, where the duration of radiated UWB carrier pulse is enlarged considerably to get enough energy per bit and the duration of received UWB pulse is compressed by a matched filter at the receiver, is introduced in this contribution. The increased bit energy increases the radio coverage and the envelope of compressed UWB pulse satisfies the requirements of IEEE Std. 802.15.4a. The gains in energy per bit are about 18 dB and 22 dB when the UWB pulse durations are set to 100 ns and 300 ns, respectively.