Results 261 to 270 of about 37,496 (307)

Frequency domain IQ imbalance estimation in the presence of DC offset and frequency offset

2009 IEEE 20th International Symposium on Personal, Indoor and Mobile Radio Communications, 2009
Direct conversion receivers in orthogonal frequency division multiplexing (OFDM) systems suffer from direct current (DC) offset, frequency offset, and IQ imbalance. We have proposed an IQ imbalance estimation scheme in the presence of DC offset and frequency offset, which uses preamble signals in the time domain.
Mamiko Inamori, Shuzo Takayama, Yukitoshi Sanada   +2 more
openaire   +1 more source

Pilot-based frequency offset estimation in the presence of time-varying DC offset

2009 IEEE 20th International Symposium on Personal, Indoor and Mobile Radio Communications, 2009
In OFDM systems, since carrier frequency offset (CFO) destroys the orthogonality among subcarriers, whose estimation/compensation is a critical problem. However, the CFO estimation suffers from DC offset (DCO) generated in low-cost direct-conversion receivers (DCRs). More seriously, in general, DCO is time-varying due to the automatic gain control.
Umut Yunus, Hai Lin 0001, Katsumi Yamashita   +2 more
openaire   +1 more source

BLE Receiver with Fast DC Offset Cancellation and Carrier Frequency Offset Compensation

2021
A BLE receiver with fast DC offset cancellation and carrier frequency offset (CFO) compensation is presented. The receiver employs a fully integrated RF front-end and a digital modem. The BLE SoC with embedded flash is fabricated in 55 nm RF CMOS technology, the receiver achieves sensitivity of −95 dBm and the CFO compensation in digital modem helps to
openaire   +1 more source

A novel dynamic DC-offset canceller

2003 5th International Conference on ASIC Proceedings (IEEE Cat No 03TH8690) ICASIC-03, 2003
A dynamic Direct Current (DC)-offset canceller in a receiver of a communication system is presented. The dynamic DC-offset voltage is sampled and then a loop architecture is used to cancel the DC-offset voltage. The simulated results show that the DC-offset voltage is no more than 5 mV after the loop architecture is operated.
null Haiyong Wang, null Min Lin, null Yongming Li, null Hongyi Chen   +3 more
openaire   +1 more source

DC Offset Mitigiation in Homodyne Receiver

2005 5th International Conference on Information Communications & Signal Processing, 2006
The benefits and implementation issues of the homodyne receiver architecture in mobile handsets is presented, with a review of some current techniques used to mitigate the dc-offset generated due to local-oscillator (LO) leakage self-mixing, and a simplified solution is ...
M. Osoba, J. Irvine, R. Stewart, D. Crawford, F. Westall   +4 more
openaire   +1 more source

Elimination of DC Offset by MMSE Adaptive Equalizers

IEEE Transactions on Communications, 1976
Data communication systems are often beset with the problem of dc offset. The questions addressed and answered in this concise paper are: 1) can minimum mean-squared error (MMSE) equalizers correct dc offset? 2) what are the exact effects of the equalizer on offset, and offset on residual MSE?
openaire   +1 more source

A DC-coupled biomedical radar sensor with analog DC offset calibration circuit

2018 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), 2018
A common problem of biomedical radar sensors is the DC offset at the output of radar receiver front-end. In this paper, a DC-coupled Doppler radar sensor system with an analog DC offset calibration circuit is proposed. The calibration circuit can track the change of DC offset continuously, and automatically remove the offset on the fly or in a ...
Dongyang Tang, Jing Wang 0064, Zhengyu Peng, Yi-Chyun Chiang, Changzhi Li   +4 more
openaire   +1 more source

Dynamic synchrophasor estimation in the presence of decaying DC offsets

2014 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Proceedings, 2014
Electrical waveform phasor measurements are receiving a steadily increasing interest due to their relevance in smart grid applications. In particular, the Taylor-Weighted Least Squares (TWLS) algorithm has been recently proposed for the estimation of the waveform phasor in dynamic conditions.
Daniel Belega, Dario Petri
openaire   +1 more source

Photonics-Based Microwave Phase Detector With Reduced DC Offset and Phase Offset

IEEE Photonics Technology Letters, 2020
A cascaded optical modulator topology for detecting the phase difference of two microwave signals is presented. It operates based on mixing of two microwave signals. The phase difference of two microwave signals can be obtained from the system output DC voltage.
Hao Chen, Erwin H. W. Chan
openaire   +1 more source

The effect of DC offset on current-operated relays

IEEE Transactions on Industry Applications, 1998
When a fault occurs on a power system, one or more phases will experience DC offset. This DC component, which will decay dependent on the L/R time constant of the system, can produce saturation in the current transformers, as well as the input current transformers of the protective relays sensing the fault.
openaire   +1 more source