Impulse Radio Ultra-wideband Communication Systems Research Articles

An Optimized IR-UWB Communication System with Interference Reduction on a Narrowband System Using Genetic Algorithm

This paper proposed a new impulse radio ultra wideband (IR-UWB) signal to reduce interference on narrowband systems at high usage 5.2 GHz frequency. The combination of 4th and 5th order derivatives of Gaussian pulses were employed to generate the signal so that satisfy the US Federal Communications Commission (FCC) mask. The genetic algorithm technique was used to find the pulse optimized parameters. In this paper, spectrum was optimized by changing the shape factor (sigma) and amplitude of Gaussian pulses so that the transmitted power spectrum density was minimized at a frequency of 5.2 GHz and maximized at the other frequencies from 3.1 to 10.6 GHz according to the FCC mask. The signal was applied in an IR-UWB transceiver system with binary-phase shift keying modulation. The IR-UWB waveform is generated by a programmable digital to analog based circuit. The proposed system was compared with conventional IR-UWB systems at the same condition. The simulation results in multipath channel showed that the proposed system not only reduced interference with the narrowband system, but also this was robust against narrowband interference at 5.2 GHz frequency.

Joint VMIMO and LDPC Decoders for IR-UWB Wireless Body Area Network

A complete impulse radio-ultra wide band (IR-UWB) system is proposed to mitigate the impairments concerning on-body to off-body Wireless Body Area Networks (WBAN). The proposed system maintains the practical communication link between on-body sensors to the fusion center or the monitoring device held by the medical representative. Also, these sensors are assigned a recently proposed pulse shaping to mitigate the noise that existed in the IR-UWB WBAN channel. Furthermore, virtual multiple-input multiple-output (VMIMO) is proposed to perform spatial multiplexing between various sensors transmitted data. Moreover, low complex low density parity check (LDPC) encoding/decoding algorithms, including a new low complex hybrid LDPC decoding algorithm, are proposed to reduce the complexity and to enhance the bit error rate of the on-body sensors. Interestingly, low energy consumption at every sensor participating in the on-body to off-body WBAN was achieved by adopting the combination between LDPC decoders and VMIMO technique. According to simulation results, the new system enhanced the BER performance and reduced the complexity of the on-body to off-body IR-UWB communication system effectively.

QPSK Modulation Scheme Based on Orthogonal Gaussian Pulses for IR-UWB Communication Systems

A new impulse radio-ultra wideband (IR-UWB) communication system with quadrature phase shift keying (QPSK) modulation scheme was presented in this research. The system utilized orthogonal property of fourth- and fifth-order derivatives of Gaussian pulses for modulation and time hopping (TH) multiple-access scheme. This system was compared with conventional TH-PPM and TH-BPSK systems at the same condition. The simulation results in multipath channel showed that the proposed system can provide better bit rate performance compared with the conventional IR-UWB system. A very low power and low complexity circuit for generation of the fourth-order derivative of Gaussian pulse was also proposed. The circuits of fourth- and fifth-order derivatives of Gaussian pulses were simulated using a 0.18[Formula: see text][Formula: see text]m CMOS technology. The core chip size was only 0.015[Formula: see text]mm2. The output amplitude pulse yielded 135[Formula: see text]mV peak to peak under a supply voltage of 1.8[Formula: see text]V. The energy consumption of the fourth- and fifth-order derivatives of Gaussian pulses circuits were 8[Formula: see text]pJ/pulse for 200[Formula: see text]MHz pulse-repeating frequency (PRF).

Differentially-Keyed IR-UWB Signals for MA with Differential-Detection Receiver

Noncoherent communication receivers (differential-detectors) have simple design, however, they always incur bit error rate (BER) performance loss up to 3dB compared to coherent receivers. In this paper, a differential-detector is proposed for impulse radio ultra wideband (IR-UWB) communication systems. The system employs bit-level differential phase shift keying (DPSK) combined with code division (CD) for IR-UWB signals to support multiple-access (MA). It is analyzed under additive white Gaussian noise (AWGN) corrupted by multiple-access interference (MAI) channel. Its BER performance is compared against a reference coherent receiver using Monte-Carlo simulation method. A closed form expression for its average probability of error is derived analytically. Simulation results and theoretical analysis confirm the applicability of the proposed differential-detector for IR-UWB communication systems.

The Fractal Characteristics of Signals in IR-UWB Communication System

In this paper the fractal characteristics of the received multipath signals of impulse radio ultra-wideband communication system are analyzed and proved using over-value function. The scale-invaria...

Optimal receiver antenna location in indoor environment using dynamic differential evolution and genetic algorithm

Abstract Using the impulse responses of these multipath channels, the bit error rate (BER) performance for binary pulse amplitude modulation impulse radio ultra-wideband communication system is calculated. The optimization location of receiving antenna is investigated by dynamic differential evolution (DDE) and genetic algorithm (GA) to minimize the outage probability. Numerical results show that the performance for reducing BER and outage probability by DDE algorithm is better than that by GA.

Performance of Multi Pulse Position Amplitude Modulation for TH IR-UWB Communication Systems

The multi pulse position amplitude modulation scheme for time-hopping multiple access impulse radio ultrawideband communication systems has been presented in this paper. Multi pulse position amplitude modulation is a hybrid modulation technique, which combines multi pulse position modulation and pulse amplitude modulation. It is shown that multi pulse position amplitude modulation significantly outperforms pulse position modulation with respect to bandwidth efficiency. The multi pulse position amplitude modulation error probability over IEEE 802.15.3a multipath fading channels in multiuser environment is derived. The system analysis shows that the proper selection of modulation parameters can improve the system performance at the cost of hardware complexity (and vice versa).

Performance Analysis and Optimization of $\hbox{T}_{\rm c}$-DTR IR-UWB Receivers Over Multipath Fading Channels With Tone Interference

In this paper, we analyze the performance of a particular class of transmitted-reference receivers for impulse radio ultrawideband communication systems, which is called chip-time differential transmitted-reference ( <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{T}_{\rm c}$</tex></formula> -DTR). The analysis aims at investigating the robustness of this receiver to single-tone and multitone narrowband interference (NBI) and comparing its performance with other noncoherent receivers that are proposed in the literature. It is shown that the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{T}_{\rm c}$</tex></formula> -DTR scheme provides more degrees of freedom for performance optimization and that it is inherently more robust to NBI than other noncoherent receivers. More specifically, it is analytically proved that the performance improvement is due to the chip-time-level differential encoding/decoding of the direct sequence (DS) code and to an adequate design of DS code and average pulse repetition time. The analysis encompasses performance metrics that are useful for both data detection (i.e., average bit error probability) and timing acquisition (i.e., false-alarm probability <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{P}_{\rm fa}$</tex></formula> and detection probability <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{P}_{\rm d}$</tex></formula> ). Moving from the proposed semianalytical framework, the optimal code design and system parameters are derived, and it is highlighted that the same optimization criteria can be applied to all the performance metrics considered in this paper. In addition, analytical frameworks and theoretical findings are substantiated through Monte Carlo simulations.

A new modulation scheme for IR-UWB communication systems

Since the poor performance of orthogonal binary Pulse Position Modulation (PPM) compared with binary Pulse Amplitude Modulation (PAM), this paper presents a new modulation scheme named Pulse Width Modulation (PWM) for Impulse Radio Ultra-WideBand (IR-UWB) communication systems. This modulation scheme uses pulses with equal amplitude and different widths to carry different information. The receiver employs differences between similarity coefficients among these pulses to distinguish different information. Both theoretical analysis and simulation results verify that this novel scheme has a Signal to Noise Ratio (SNR) gain of about 1.75 dB compared with orthogonal binary PPM, and has an SNR loss of about 1.4 dB compared with binary PAM. Although both the theoretical analysis and simulations are based on time-hopping multiple access, this modulation scheme can also be applied to other accessing techniques of UWB communication systems.