Orthogonal frequency division multiplexing (OFDM) suffers from a high peak to average power ratio (PAPR). Tone reservation (TR) technology is considered as one of the most promising methods because of no additional distortion, no side information, and low implementation cost. However, in all PAPR reduction schemes,determining the optimal target clipping level is difficult. In this paper, we con...

Orthogonal frequency division multiplexing (OFDM) suffers from a high peak to average power ratio (PAPR). Tone reservation (TR) technology is considered as one of the most promising methods because of no additional distortion, no side information, and low implementation cost. However, in all PAPR reduction schemes, determining the optimal target clipping level is difficult. In this paper, we co...

In this paper, the Peak-to-Average Ratio reduction in OFDM systems is implemented by the Adaptive Active Constellation Extension (ACE) technique which is more simple and attractive for practical downlink implementation purpose. However, in normal constellation method we cannot achieve the minimum PAR if the target clipping level is much below than the initial optimum value. To get the better of...

This report presents two cases of subarachnoid hemorrhage caused by rupture of paraclinoid aneurysms. Both aneurysms presented a bilobulated appearance upon image study. Both cases were treated successfully, the first with surgical clipping and the second with endovascular coiling. The special bilobulated feature of paraclinoid aneurysm in this particular anatomic location suggests its close re...

Orthogonal Frequency Division Multiplexing (OFDM) has become the popular modulation technique in high speed wireless communications. One of the main disadvantages of Orthogonal Frequency Division multiplexing (OFDM) is its high Peak-to-Average Power Ratio (PAPR), which significantly reduces the efficiency of the High Power Amplifier (HPA). Due to the simplest way for PAPR reduction, clipping te...

Cases of spontaneous regression of cerebral aneurysm remnant after incomplete surgical clipping have been rarely reported. This paper reports the regression of an aneurysm remnant after incomplete surgical clipping during postsurgical follow-up. A 50-year-old male presented with subarachnoid hemorrhage because of rupture of an anterior communicating artery aneurysm. An emergency clipping of the...

This paper presents performance analysis of Peak to Average Power Ratio (PAPR) Reduction techniques in Orthogonal Frequency Division Multiplexing (OFDM) System such as Clipping, Partial Transmit Sequence (PTS), Selective Mapping (SLM) and SLM with Clipping (Hybrid Scheme) .Complementary Cumulative Distribution Function (CCDF) is calculated for each technique with different number of sub carrier...

Clipping bilateral middle cerebral artery (bMCA) aneurysms via unilateral approach in a single-stage operation is considered as a challenge procedure. To our knowledge, there is no study in surgical management of patients with bMCA aneurysms by fully endoscope-controlled techniques. The author reported a patient with bMCA aneurysms who underwent aneurysms clipping via a unilateral supraorbital ...

—High peak-to-average ratio power (PAPR) is a critical practical problem for an OFDM system. Many techniques, such as clipping and filtering (ICF), cognitive clipping, have been proposed to deal with the issue. However, it needs to determine the relationship between error vector magnitude (EVM) and clipping ratio (CR). In this paper, we formulate a universal PAPR optimization model with EVM co...

OBJECTIVES To compare endovascular coiling with neurosurgical clipping of ruptured basilar bifurcation aneurysms. METHODS Patient and aneurysm characteristics, procedural complications, and clinical and anatomical results were compared retrospectively in 44 coiled patients and 44 patients treated by clipping. The odds ratios for poor outcome (Glasgow outcome scale 1, 2, 3) adjusted for age, c...