A Multiband, Spectrally-Efficient Impulse Radio Transmitter Design with Low-Complexity CMOS Pulse Generator for IEEE 802.15.4a Application

A novel multiband impulse radio ultra-wideband (MB-IR-UWB) transmitter with an energy-efficient and low-complexity pulse generator design technique compliant with the IEEE 802.15.4a standard is investigated in this paper. This transmitter is made up of a new differential narrow triangular pulse generator, a new multiband voltage-controlled oscillator (VCO), an active mixer and a variable-gain power amplifier (PA). It operates at 14 UWB bands and generates an output signal with the duration of 3[Formula: see text]ns, more than 500[Formula: see text]MHz of channel bandwidth and more than 20[Formula: see text]dB of sidelobe suppression, while achieving an average energy efficiency of 51.36 pJ/pulse from 1.4-V supply. Improving spectral flexibility and worldwide compliance is the major contribution brought by this paper to make this circuit as a multifunction wireless device well suited for low-cost, low-power multiband applications.

Multi-Layer Wireless Perception and Recognition Technology Based on Internet of Things

To study the multi-layered wireless sensation and recognition technology of the Internet of Things, the background and research status at home and abroad were summarized. An IoT system architecture based on a multi-layer multi-reader passive network and a technology for simultaneous simulation of multiple network standards based on OMNeT++ were proposed. The proportion of the time consumption of each communication phase in the entire communication process was analyzed in detail. A variety of strategies for shortening the system delay were proposed. At the same time, multiple network standard protocol stacks were divided and modeled. Dual-layer networks based on IEEE 802.11 and IEEE 802.15.4a were verified as examples. The results showed that the length of the hop sequence and the number of readers were optimized. Therefore, this method is effective.

Improved energy detection receiver for ranging in IEEE 802.15.4a standard

In this paper, we propose a novel energy detection (ED) receiver architecture combined with time-of-arrival (TOA) estimation algorithm, compliant to the IEEE 802.15.4a standard. The architecture is based on double overlapping integrators and a sliding correlator. It exploits a series of ternary preamble sequences with perfect autocorrelation property. This property ensures coding gain, which allows an accurate estimation of power delay profile (PDP). To improve TOA estimation, the interpolation of PDP samples is proposed and the architecture is validated by using an ultra-wideband signals measurements platform. These measurements are carried out in line-of-sight and non-line-of-sight multipath environments. The experimental results show that the ranging performances obtained by the proposed architecture are higher than those obtained by the conventional architecture based on a single-integrator in both LOS and NLOS environments.

Channel Loss Estimation and Test of Ultra-Wideband Propagation from 2 to 10 GHz Application

<p>This paper deals with the channel loss models of ultra-wideband radio wave propagation from 2 to 10 GHz application. IEEE 802.15.4a and Okumura channel loss reference models have been introduced and the estimation methods of channel transmission loss have been discussed with the environments of 2 to 10 GHz short range application. The channel transmission loss was measured in ZigBee circuit with 2 kinds of power, using IEEE 802.15.4a and Okumura channel model to estimate the theoretical channel loss, the theoretical value and the actual measured value were compared and analyzed. The analysis shows that the error between the calculated value and the actual measured value of the IEEE 802.15.4a reference model is small in the ultra-wideband ZigBee channel environment, and the error of the Okumura channel loss model is large. The results show that in the environments of 2 to 10 GHz short range application, IEEE 802.15.4a channel loss model is a high precision reference model for the ultra-wideband channel loss calculation.</p>