UWB signal acquisition in transmit-only networks

This paper presents a novel method for signal acquisition in UWB-based transmit-only wireless sensor networks where concurrent transmissions are unavoidable and power control is infeasible. In such a scenario, the conventional CDMA approach where different sensor nodes have different spreading codes, suffers from the near-far effect and difficulty in code assignment. The proposed single-code method employing the low-duty-cycle DS-UWB signal turns the near-far problem to a near-far advantage and greatly simplifies the system complexity. The performance and implementation cost of our proposal are compared with other approaches, such as the CDMA approach employing the low-duty-cycle DS-UWB signal, the single-code approach employing the high-duty-cycle DS-UWB signal, the TH-UWB signal and the TH/DS-UWB signal. The results show that the proposed method has better performance and simpler implementation in the transmit-only scenario.