Low power frequeney-to-time conversion for cellular systems using predictive zero-crossing

Trans Emerging Tel Tech

Jung

2007

SUMMARYShort range communication systems such as Bluetooth and DECT (Digital Enhanced Cordless Telecommunications) deploy Gaussian frequency shift keying (GFSK), which is a continuous phase modulation (CPM) scheme derived from minimum shift keying (MSK). Since these short range communication systems require low-cost transceiver structures, the development of appropriate receiver techniques has been a major research topic. Particularly, analogue limiter-discriminator-integrator (LDI) dump filtering techniques have received considerable attention. With the availability of digital signal processing (DSP), the digital implementation of LDI techniques has become increasingly attractive. In order to make LDI receivers more accessible, zero-crossing detection was proposed. First, the authors shall focus on the establishment of an appropriate mathematical discrete-time system model, taking bandlimiting receiver filters into account explicitly. This system model serves as the basis for the development of a multitude of digital zero-crossing detection techniques. Starting from this mathematical discrete-time system model, the authors shall focus on a novel, yet promising, approach to digital zero-crossing detection in the intermediate frequency domain, using irregular sampling instead of the commonly employed regular sampling. The novel detectors shall be termed zero-crossing decorrelation detectors (ZXDDs), because a decorrelating approach will be used. The authors shall present three different variants of the ZXDD. The performance of these ZXDD schemes has been analysed in simulations by the authors and obtained results shall be presented and compared to the performance of known LDI and zero-crossing detection based techniques.

Section: Introductionmentioning

confidence: 99%

Intermediate frequency zero‐crossing detection of filtered MSK based on irregular sampling

Trans Emerging Tel Tech

Jung

2007

“…Their design already paved the way to the implementation of zero-crossing detection in the IF domain, which was revisited by Dutta et al [28], also from an implementation point of view. Dutta et al reported a low-implementation complexity, as well.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, a bandpass filter with impulse response c BP (τ ) is abblied by the RF-IF downconversion unit. The zero-crossing detector shall be devised like in Figure 1b [12,28], choosing N div = 1.The zero-crossing detector converts its input signal to digital representations of the distances beween sucessive zero-crossings of the input signal. The sync/sample select unit will cover the syncronization and converts the irregular sampled signal into a regular sampled version by following the idea of analog LDI receivers using digital signalprocessing.…”

Section: Introductionmentioning

confidence: 99%

A Real-Time Zero-Crossing Demodulation Concept

Spiegel

Waadt

et al. 2006

Wireless Pers Commun

Short range communication systems such as Bluetooth and Digital Enhanced Cordless Telecommunications require low-cost transceiver structures. Hence, the development of appropriate receiver techniques has been a major research topic. Particularly, analog limiter-discriminator with integrate and dump filtering (LDI) techniques have received considerable attention. With the availability of digital signal processing, the digital implementation of LDI techniques has become increasingly attractive. In order to make LDI receivers more accessible, zero-crossing detection was proposed. In this communication, the authors shall focus on a novel, yet promising, approach to digital zero-crossing detection in the intermediate frequency domain. Zero-crossing demodulation is an irregular sampling technique, which replaces the commonly employed regular, i.e. temporally equidistant sampling technique in the mentioned low-cost receivers. In this manuscript, a real-time capable receiver concept deploying zero-crossing demodulation shall be presented. First, the authors shall present the theoretical aspects of zero-crossing demodulation with special focus on both Bluetooth Basic Rate and Bluetooth Enhanced Data Rate. Next, the obtained performance results in terms of the bit error ratio shall be given.Keywords: π /4-Shifted differential quadrature phase shift keying, bluetooth, bluetooth basic rate, Bluetooth enhanced data rate, continuous phase modulation, differential phase shift keying, digital enhanced cordless telecommunications, frequency modulation, Gaussian frequency shift keying, minimum shift keying, octal differential phase shift keying, real-time implementation, zero-crossing demodulation.

“…(8)). Zerocrossing detectors, paving the way to irregular sampling and therefore representing a rather unconventional point of view to data detection, provide low implementation complexity to CPM [9] with, however, considerable performance degradations.…”

Section: Introductionmentioning

confidence: 99%

New Intermediate Frequency Zero-Crossing Detector for MSK Signals

GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)

Jung

Short range communication systems such as Bluetooth and DECT (Digital Enhanced Cordless Telecommunications) deploy GFSK (Gaussian Frequency Shift Keying) modulation which has been derived from MSK (Minimum Shift Keying).In this communication, the authors discuss and analyze an improved zero-crossing detector for MSK signals, deploying a least squares (LS) approach. The novel detector shall be termed zero-crossing decorrelation detector (ZXDD). The impact of bandlimitation due to bandpass filtering shall be taken into account, explicitely.