91 research outputs found
Joint compensation of IQ-imbalance and carrier phase sychronization errors in communication receivers
No full textThis work addresses the joint compensation of IQimbalances
and carrier phase synchronization errors of zero-
IF receivers. The compensation scheme based on blind-source separation which provides simple yet potent means to jointly compensate for these errors independent of modulation format
and constellation size used. The low-complexity of the
algorithm makes it a suitable option for real-time deployment as well as practical for integration into monolithic receiver designs
Performance of an adaptive homodyne receiver in the presence of multipath, Rayleigh-fading and time-varying quadrature errors
No full textIn this paper, we carry out a detailed performance analysis of the blind source separation based I/Q corrector operating at the baseband. Performance of the digital I/Q corrector is evaluated not only under time-varying phase and gain errors but also in the presence of multipath and Rayleigh fading channels. Performance under low-SNR and different modulation formats and constellation sizes is also evaluated. What is more, BER improvement after correction is illustrated. The results indicate that the adaptive algorithm offers adequate performance for most communication applications hence, reducing the matching
requirements of the analog front-end enabling higher levels of integration
Adaptive compensation of analog front-end I/Q mismatches in digital receivers
No full textI and Q Channel phase and gain misniatches are of great concern in communications receiver design. In this paper we analyse the effects of I and Q channel mismatches and propose a low-complexity blind adaptive algorithm to minimize this problem. The proposed solution consists of two, 2-tap adaptive filters, arranged in Adaptive Noise Canceller (ANC) set-up, with the output of one cross-fed to the input of the other. The system works as a de-correlator eliminating I and Q mismatch errors
On the performance of a blind source separation based I/Q-corrector
No full textI and Q Channel phase and gain mismatches are of great concern in communications receiver design. In this paper we carry out a detailed performance analysis of the Blind-Source Seperation (BSS) based imbalance compensation structure. The results indicate that the BSS structure can offer adequate performance for most communication systems. Since the compensation is carried out before any modulation specific processing, the proposed compensation method works with all standard modulation formats
A new bulk-driven input stage design for sub 1-volt CMOS op-amps
No full textThis paper presents a new design approach for a rail-to-rail bulk-driven input stage using a standard single-well (n-well in this paper) CMOS technology. This input stage can provide nearly constant transconductance and constant slew rate over the entire input common-mode voltage, operating with a wide supply voltage ranging from sub 1-volt (V/sub T0/+ 3V/sub DSsat/) to the maximum allowed for the CMOS process, as well as preventing latch-up
Adaptive digital receivers for analog front-end mismatch correction
No full textPhase and gain mismatches between the I and Q analog signal processing paths of a quadrature receiver are responsible for the generation of image signals which limit the dynamic range of a practical receiver. In this paper we analyse the effects these mismatches and propose a low-complexity blind adaptive algorithm to minimize this problem. The proposed solution is based on two, 2-tap adaptive filters, arranged in Adaptive Noise Canceller (ANC) set-up. The algorithm lends itself to efficient real-time implementation with minimal increase in modulator complexity
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