This paper proposes a novel UWB ranging scheme employing 1-bit ADCs and analog window bank for energy collection. For an appropriate 1-bit ADC process DC offset is exploited and removed via performing analog low pass filter. To improve ranging accuracy in presence of ambiguity, dual overlapped window banks designated as primary and auxiliary windows are utilized. Corresponding to the proposed ranging scheme, its performance is verified by conducting simulations in two types of channel conditions. The simulation results show that the proposed ranging scheme performs well even in condensed multipath environment and low SNR situation.

The explosive growth of wireless network users and the existence of various wireless services have demanded high throughput as well as user's quality-of-service (QoS) guarantees. In accordance with, this paper proposes a novel resource allocation scheme improving both the capability of QoS-provisioning for multiple users and the overall data throughput. Towards this, the modified resource allocation technique combined with the modified largest weighted delay first (M-LWDF) scheme will be exploited upon considering statistical channel behavior as well as real time queuing analysis connected to resource allocation. In order to verify the validity of the proposed resource allocation scheme, the time division multiple access (TDMA) system will be considered as a target application. The simulation results confirm that the proposed scheme gives rise to superior performance in a way of showing results of several performance measures under time-varying wireless fading channel.

During the execution of precise ranging in the time domain, the most important fact to consider is how to achieve an accurate estimate of the time corresponding to first arrival of the transmitter. However, it is difficult to extract an estimate of the time-of-arrival (TOA) through use of a simple correlator due to degradation on correlation, and in the case where the pulse repetition interval (PRI) is less than the maximum excess delay (MED). In order to enhance the correlation capability, this paper proposes a TOA estimation method that obeys a threshold predetermined in a non-coherent system using multiple-mask operation (MMO). The performance of the proposed scheme is verified by conducting simulations under two different types of channel situations. The simulation results show that the proposed scheme performs well even in a dense indoor multipath environment and with the existence of multiple simultaneously operating piconets (SOPs).

This paper introduces an efficient affine projection algorithm (APA) using iterative hyperplane projection. The inherent effectiveness against the rank deficient problem has led APA to be the preferred algorithm to be employed for various applications over other variety of fast converging adaptation algorithms. However, the amount of complexity of the conventional APA could not be negligible because of the accomplishment of sample matrix inversion (SMI). Another issue is that the "shifting invariance property," which is typically exploited for single channel case, does not hold ground for space-time decision-directed equalizer (STDE) application deployed in single-input-multi-output (SIMO) systems. Therefore, fast adaptation schemes, such as fast traversal filter based APA (FTF-APA), becomes impossible to utilize. The motivation of this paper deliberates on finding an effective algorithm on the basis of APA, which yields low complexity while sustaining fast convergence as well as excellent tracking ability. The performance of the proposed method is evaluated under wireless SIMO channel in respect to bit error rate (BER) behavior and computational complexity, and upon completion, the validity is confirmed. The performance of the proposed method is evaluated under wireless SIMO channel in respect to bit error rate (BER) behavior and computational complexity, and upon completion, the validity is confirmed.

Repeaters equipped with on-board digital baseband processing in a time division duplex (TDD) demand short processing time in order to alleviate inter-symbol interference resulting from having a time delay that is greater than the guard time. To accomplish this, the total system delay of the repeater should be minimized as much as possible without distorting signal quality. Conventionally, the finite impulse response (FIR) type of filter is deployed as a channelization filter, but due to the necessity of large numbers of coefficients to fulfill a prerequisite filter response with a sharp transition band characteristic, an unwanted excessive time delay intrinsically occurs. To make the processing delay as low as possible, this paper proposes a method employing a minimum-phase characterized infinite impulse response (IIR) filter whose magnitude response is almost identical to that of the original FIR filter. Furthermore, in order to linearize the phase response of the designed IIR filter, this paper also introduces an all-pass filter cascaded with the IIR filter for digital down-conversion as well as up-conversion. To achieve further simplicity, this paper introduces polyphase-style IIR filters transformed from conventional single IIR filters that have their own all-pass filters in order to linearize the phase response. The computer simulation results verify that the proposed integrated IIR filter exhibits a relatively short processing delay with a minor deterioration in signal quality-like error vector magnitude (EVM) performance.

This paper proposes the joint beamforming space-time block coding (JBSTBC) scheme for multi-input multi-output (MIMO) communication systems. To enhance the order of spatial diversity in presence of deteriorate fading correlations as well as inter-substream interferences, the proposed JBSTBC method employs joint eigen-beamforming technique together with the block-ordered layered detector (BOLD) for MIMO-STBC. In order to confirm the superiority of the proposed JBSTBC method, computer simulations are conducted in highly correlated fading situations while providing detailed mathematical derivations for clarifying functionality of the proposed scheme.

This paper discusses the implementation of multi-band digital intermediate frequency (IF) for wideband CDMA (W-CDMA) transceiver. The majority of the implemented module in hardware is composed of wideband analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and field programmable-gated-arrays (FPGA). And in software, it is coded by VHSIC hardware description language (VHDL) for realizing digital filters and numerically controlled oscillator, etc. To cope with the hardware limitation such as the number of gates in FPGA, the overall digital filter embedded in transceiver is constructed via a cascading a series of decimation and interpolation filters. At transmitter, in order to upconvert the multi-band baseband channels simultaneously, two-stage digital complex quadrature modulation (DCQM) is utilized. The relevant up-and-down conversion of the numerically controlled oscillator (NCO) is designed in the form of a look-up-table (LUT), having samples associated with a sampled sinusoidal with period of 1/4. At receiver, to avoid the usage of surface acoustic wave (SAW) filter, the high-performance digital filter is implemented subject to satisfying band rejection ratio prescribed in blocker and adjacent channel specification. This paper provides the performance of the implemented digital IF module by revealing the results taken from the measurement instruments. Moreover, to confirm its validity computer simulations are simultaneously conducted.