On the performance of coherent and noncoherent UWB detection systems using a relay with multiple antennas

A cooperative approach for amplify-and-forward differential transmitted reference IR-UWB relay systems

“…In order to extend the coverage, amplify-and-forward (A&F) and decode-and-forward (D&F) relaying techniques, which were originally proposed for narrowband communications [7], have been also applied to the context of IR-UWB DTR receivers [8], [9]. A critical issue in A&F relaying lies on the length of the overall channel impulse response (CIR) that increases with the number of hops.…”

Ultra Wideband Systems with MIMO

“…Up to now, freedoms F1, F3, F4 and F6 were partly examined in [9,[147][148][149][150], and freedom F5 was mentioned in [45,46]. Freedom F2 remains unexplored, and there are many options for freedom F3.…”

“…Note that, in [149], the multiple antennas are used for the purposes of both reception and transmission at the relay node, and the gain thus obtained will be doubled compared with the cases in which these antennas are deployed either at the source node or at the destination node. Since UWB systems typically use Rake receivers to collect the energy spread over multipaths and the number of Rake fingers is an important factor which affects the complexity/cost of UWB systems, the compromise between the number of antennas at the relay node and the number of Rake fingers was investigated in [147,148]. The results show that generally increasing the number of antennas at the relay node yields better BER performance than increasing the number of Rake fingers for a fixed product of the two numbers.…”

“…The results show that generally increasing the number of antennas at the relay node yields better BER performance than increasing the number of Rake fingers for a fixed product of the two numbers. In [150], the results of [147,148] are extended to the case where multiple antennas are also equipped at the source and destination nodes. In [148], a differential coded transmitted-reference (DCTR) relay system is proposed, by which the traditional synchronizer and Rake receiver can be removed.…”

“…In [150], the results of [147,148] are extended to the case where multiple antennas are also equipped at the source and destination nodes. In [148], a differential coded transmitted-reference (DCTR) relay system is proposed, by which the traditional synchronizer and Rake receiver can be removed. As is well known, the design of synchronizers for UWB receivers is a critical and not yet fully solved issue, and the Rake receiver with a reasonable number of fingers considerably increases the complexity/cost of UWB systems.…”