Channel division multiple access : new multiple access approach for UWB networks

During the last years, Ultra-WideBand (UWB) has been presented as a promising radio technology due to the large bandwidth available. This feature enables point to point high data rates at short range as well as high temporal resolution with long Channel Impulse Responses (CIR). Due to the their large bandwidth, UWB systems enables high temporal resolution with long CIR. In this paper, we propose and evaluate an original multiple access scheme called Channel Division Multiple Access (ChDMA). The idea behind the ChDMA is to use the CIR of each user as a signature, i.e., the signature code is given by the channel and the users are separated as a CDMA system. It is important to note that the signatures are given by the environment and by user’s position, which means that they are uniquely determined. This signature location-dependent property provides decentralized flexible multiple access as the codes are naturally generated by the radio channel. The framework was analyzed and validated by capacity assessments using UWB measurements and compared with classical CDMA schemes with random spreading codes. The analysis is focused on the impact of the user’s asynchronism and the period of symbol on system performance. Two structures are considered at the receiver: single-user matched filter and MMSE receiver with Gaussian and BPSK signaling schemes.