Transmitted Reference Pulse Cluster System Research Articles

An Energy Efficient On-Off Keying Transmitted Reference Pulse Cluster System for UWB Communications

In order to overcome the long wideband delay line issue of conventional transmitted reference (TR) ultra-wideband (UWB) systems, a transmitted reference pulse cluster (TRPC) structure was proposed and many related studies have been done. This paper presents a new on-off keying TRPC (OOK-TRPC) structure which can save half of the transmitting energy of the original TRPC scheme. Based on this new structure, an energy detector (ED) is applied and estimating methods for its symbol decision threshold are designed under different signal-to-noise ratio conditions. Analytical and simulation results show the energy efficiency of the proposed OOK-TRPC ED scheme. Therefore, from a practical point of view, the designed OOK-TRPC ED, which also can be applied to some previous TRPC related studies, is considered as a highly recommended practice, particularly in wireless sensor networks, internet of things, and wireless body area networks etc, where energy-saving has been becoming increasingly crucial.

Hybrid PPM-BPSK for Transmitted Reference Pulse Cluster Systems in UWB and 60-GHz Channels

Transmitted reference pulse cluster (TRPC) is an impulse radio technology developed for ultrawideband (UWB) communications that achieves superior performance among noncoherent (NC) schemes with low complexity. It employs binary phase-shift keying (BPSK) in the pulse cluster to carry information. In this letter, a hybrid pulse position modulation (PPM) and BPSK is introduced into the TRPC to improve energy efficiency and/or increase data rate. Two types of bit-to-pulse cluster mapping are proposed, one of which is termed Gray PPM-BPSK. It is shown by analysis and simulation that, compared with the original BPSK-TRPC, the new Gray PPM-BPSK-based TRPC not only increases the data rate by a factor of 2 but also achieves 1.5-3-dB coding gain in the BER performance. The performance improvement of the proposed hybrid schemes over BPSK-TRPC and NC PPM is demonstrated over both 3-10-GHz UWB and 60-GHz millimeter-wave channels, making it a promising signaling candidate for these frequency bands.

Integration Interval Determination Algorithms for BER Minimization in UWB Transmitted Reference Pulse Cluster Systems

A recently proposed transmitted reference pulse cluster (TRPC) structure contains compactly spaced reference and data pulses, and enables a low complexity, robust and practical auto-correlation detector to be used at the receiver. Previous research indicated that the integration interval of the auto-correlation detector is critical to the performance of TRPC. Therefore, in this paper, three practical data-aided algorithms are introduced to determine the integration interval of the TRPC structure: the conventional threshold-crossing concept, the new bit error rate (BER) minimization based approach, and the new hybrid scheme that combines threshold-crossing and the BER minimization concepts. The performances of the three schemes are extensively evaluated by simulation. Results show that, the BER minimization based approach and the hybrid scheme demonstrate around 2 dB performance gain over the threshold-crossing scheme in IEEE 802.15.4a channels. Moreover, the hybrid scheme yields close performance to the BER minimization based scheme with much reduced complexity.

A New Transmitted Reference Pulse Cluster System for UWB Communications

To meet the implementation constraint posed by ultra- wideband (UWB) delay lines, a new transmitted reference pulse cluster (TRPC) structure is proposed where a group of reference and data pulses with short uniform spacing is used for transmission. This structure enables a simple, robust, and practical autocorrelation detector to be implemented in the receiver. It overcomes the major hurdle to the practical implementation of conventional transmitted reference (TR) systems, i.e., the long-wideband-delay-line requirement. TRPC is also compatible with the signal format proposed within the IEEE 802.15.4a Working Group for coherent and noncoherent systems. The performance of the proposed TRPC receiver and noncoherent pulse-position modulation (NC-PPM) with energy detection are analyzed and compared. Simulation results show that TRPC outperforms the conventional TR, NC-PPM, the recently proposed dual-pulse scheme, and the frequency-shifted reference system. In particular, it achieves power saving over NC-PPM by about 1.3-1.9 dB for IEEE 802.15.4a channel model 1 and 1.3-2.3 dB for channel model 8.