Joint Compensation of I/Q Impairments and PA Nonlinearity for Concurrent Dual-Band Transmitters using Two-Box Model

A novel two-box model for joint compensation of nonlinear distortion introduced from both in-phase/quadrature modulator and power amplifier is proposed for concurrent dual-band wireless transmitters. Compensation of nonlinear distortion is accomplished in two phases, where phases are identified separately. It is shown that complexity of the digital predistortion is reduced. The performance of the proposed model is evaluated in terms of ACPR, EVM and NMSE improvements using 1.4 MHz LTE and WCDMA signals.

Adaptive compensation of analog front-end I/Q mismatches in digital receivers

I 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.

Managerial Discretion in the Arab World: New National-Level Antecedents

Based on a sample of six Arabian countries, our study examines the effect of cultural practices on CEO discretion. Using a panel of senior consultants, we extend the national-level framework of managerial discretion and find that an encompassing array of cultural practices play a crucial role in shaping the degree of discretion provided to CEOs. We empirically demonstrate that power distance, future and performance orientation along with gender egalitarianism and assertiveness has positive relationships with managerial discretion. However, institutional collectivism, uncertainty avoidance and humane orientation negatively affect the degree of discretion provided to CEOs. As such, our results indicate that executives are able to take idiosyncratic and bold actions to the extent to which the cultural environment allows them to do so. Finally, we find new national-level antecedents of managerial discretion that haven’t been considered in earlier studies.