Efficient low-power design and implementation of IQ-imbalance compensator using early termination

In this paper, we propose a low-complexity architecture for the implementation of adaptive IQ-imbalance compensation in quadrature zero-IF receivers. Our blind IQ-compensation scheme jointly compensates for IQ phase and gain errors without the need for test/pilot tones. The proposed architecture employs early-termination of the iteration process; this enables the powering-down of the parts of the adaptive algorithm thereby saving power. The complexity, in terms of power-down efficiency is evaluated and shows a reduction by 37-50 % for 32-PSK and 37-58 % for 64-QAM modulated signals.

Design and low-power implementation of an adaptive image rejection receiver

This paper deals with and details the design and implementation of a low-power; hardware-efficient adaptive self-calibrating image rejection receiver based on blind-source-separation that alleviates the RF analog front-end impairments. Hybrid strength-reduced and re-scheduled data-flow, low-power implementation of the adaptive self-calibration algorithm is developed and its efficiency is demonstrated through simulation case studies. A behavioral and structural model is developed in Matlab as well as a low-level architectural design in VHDL providing valuable test benches for the performance measures undertaken on the detailed algorithms and structures.

Eco city development in China: addressing the policy implementation challenge

Over the last few decades, China has seen a steep rise in diverse eco city and low carbon city policies. Recently, attention has begun to focus on the perceived shortcomings in the practical delivery of related initiatives, with several publications suggesting a gap between ambitious policy goals and the emerging realities of the newly built environment. To probe this further, in this article we examine – based on the policy network approach – how the gap between high-level national policies and local practice implementation can be explained in the current Chinese context. We develop a four-pronged typology of eco city projects based on differential involvement of key (policy) actor groups, followed by a mapping of what are salient policy network relations among these actors in each type. Our analysis suggests that, within the overall framework of national policy, a core axis in the network relations is that between local government and land developers. In some cases, central government agencies– often with buy-in from international architecture, engineering and consulting firms – seek to influence local government planning through various incentives aimed at rendering sustainability a serious consideration. However, this is mostly done in a top-down manner, which overemphasizes a rational, technocratic planning mode while underemphasizing interrelationships among actors. This makes the emergence of a substantial implementation gap in eco city practice an almost predictable outcome. Consequently, we argue that special attention be paid in particular to the close interdependency between the interests of local government actors and those of land and real estate developers. Factoring in this aspect of the policy network is essential if eco city implementation is to gain proper traction on the ground.