Joint compensation of IQ-imbalance and carrier phase sychronization errors in communication receivers

This 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.

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.

Analysis and compensation of RF impairments for next generation multimode GNSS receivers

Global navigation satellite system (GNSS) receivers require solutions that are compact, cheap and low-power, in order to enable their widespread proliferation into consumer products. Furthermore, interoperability of GNSS with non-navigation systems, especially communication systems will gain importance in providing the value added services in a variety of sectors, providing seamless quality of service for users. An important step into the market for Galileo is the timely availability of these hybrid multi-mode terminals for consumer applications. However, receiver architectures that are amenable to high-levels of integration will inevitably suffer from RF impairments hindering their easy widespread use in commercial products. This paper studies and presents analytical evaluations of the performance degradation due to the RF impairments and develops algorithms that can compensate for them in the DSP domain at the base band with complexity-reduced hardware overheads, hence, paving the way for low-power, highly integrated multi-mode GNSS receivers.

Compensation of undesired effects in MIMO wireless transceivers

This paper presents compensation of all undesired effects (Power Amplifier (PA) nonlinearity, transmitter and receiver antenna crosstalk, before-PA nonlinear crosstalk, Multiple Input Multiple Output (MIMO) channel fading and crosstalk) in MIMO Orthogonal Frequency Division Multiplex (OFDM) wireless systems. It has been demonstrated that reduced-complexity Crossover Digital Predistortion (CO-DPD) algorithm on transmitter side and Matrix Inversion algorithm on receiver side can suppress almost all undesired effects introduced by transmitter, channel and receiver in 4×4 MIMO OFDM System that can be used in modern wireless system applications. A significant complexity reduction is achieved due to the fact that Digital Signal Processing (DSP) during CO-DPD process on transmitter side is done with real instead of complex numbers.

You Should Never Look a Gift Horse in the Mouth: One-Size-Fits-All Compensation in Wrongful Conception

This article reconsiders the House of Lords decision in Rees v. Darlington Memorial Hospital NHS Trust (2003) and the decision to award a conventional award of £15,000 in all cases of failed sterilisation resulting in the birth of an unwanted child. In so doing, it briefly recites the history of the Wrongful Conception action and the unique facts of Rees. It then goes on the consider the implications of two fundamental aspects of the judgment. Firstly, it looks at the 'conventional award' itself and considers the reasoning behind the award and the effect that it has on our understanding of (particularly women's) reproductive autonomy. Secondly, it analyses the rather 'unique' judgment of Lord Scott and his decision to evaluate these cases using the possessory analogy of an unwanted foal; particular focus is given to the notion of parental 'choice' in these cases and whether mitigation (i.e. abortion or adoption) can ever be considered "reasonable".

How Formal and Informal Institutions of Middle Eastern Countries Influence Managerial Discretion: An Empirical Investigation

Managerial discretion is the focal theme bridging the clash between two schools of thoughts; whether executives have greater influence on their firms’ outcomes or other factors restrain their actions (Hambrick & Finkelstein, 1987). It is argued that constraints come from inertial, normative and environmental forces (e.g. DiMaggio & Powell, 1983). Of these restraints is the institutional environment in which a firm is headquartered. Our paper falls within this research stream and provides an extension for Crossland and Hambrick (2007, 2011) work. We investigate the national level of discretion in new cross-cultural contexts, provide deeper understanding of its concept, and shed the light on undiscovered discretion’s antecedents and consequences. We adopt a quantitative approach in which questionnaires represent our data collection instrument. We anticipate that in high discretion countries firms tend to follow what Miles & Snow (1978) labeled ‘Prospector’ strategy as opposed to low discretion countries in which firms incline to implement a ‘Defender’ strategy.

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.

Cross-National Differences in Managerial Discretion: Insights from the Middle East

Our study examines the effect of cultural practices on CEO discretion across six Middle Eastern countries. Using a panel of senior management 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’ of public firms headquartered in these countries. We empirically demonstrate that power distance, future and performance orientation along with gender egalitarianism and assertiveness have 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. As such, we contribute to the strategic leadership literature by finding new national-level antecedents of managerial discretion that haven’t been considered in earlier studies and confirm the context dependency of the discretion construct.