this paper is focused on implementation of acoustic echo cancellation using modified variable step size least mean square algorithm (MVSSLMS) in LabVIEW. Simulation experiments are done to measure its performance and compared with other conventional variable step size algorithms. Results show better performance of MVSSLMS over other algorithms in terms of echo return loss enhancement (ERLE), es...

In this paper a generalized postfilter algorithm design issues are presented. This postfilter is used to jointly suppress late reverberation, residual echo, and background noise. When residual echo and noise are suppressed, the best result obtains by suppressing both interferences together after the Acoustic echo cancellation (AEC). The main advantage of this approach is that the residual echo ...

Introduction Last year the Dual-Echo PRESTO [l] technique was introduced to measure I0 and T2* simultaneously. This technique is an extension of the PRESTO [2] technique (TE > TR) and allows for the acquisition of two echoes within each TR. The first echo with a short TE (-7 ms) is acquired directly after RF excitation and is immediately followed by an echo with a long TE (-43 ms) which is echo...

PURPOSE To determine whether fast spin-echo sequences could replace conventional spin-echo methods in the evaluation of head and neck neoplasms and associated adenopathy and to evaluate differences in tissue contrast characteristics between conventional spin-echo and fast spin-echo examinations of head and neck disease. METHODS Twenty-seven patients with squamous cell carcinoma were imaged on...

Castleman disease in an 11-year-old girl appeared as a neck mass that grew despite antibiotic treatment. MR showed a well-defined solid mass, isointense with muscle on short-repetition-time/short-echo-time images, with a stellate area of central hypointensity on long-repetition-time/long-echo-time images, that did not enhance with gadolinium.

In the past, several papers have reported on echo canceler (EC) structures developed for discrete multitone transmission (DMT) based asymmetric digital subscriber lines (ADSL) transmission. The most commonly known scheme, developed by Ho, Cioffi and Bingham, is based on canceling the received echo noise efficiently in time as well as in the frequency domain. The time domain processing part, whi...

A discrete-time analog echo canceller is described that reduces the echo in the front end of Gigabit Ethernet twisted-pair interfaces. Echo cancellation in the analog domain by means of four taps reduces the complexity of the digital echo canceller and crosstalk cancellers. Designed in a 0.4m CMOS technology, the circuit employs an LMS algorithm to adapt to the cable length and impedance discon...

For full-duplex high-speed data transmission over the two-wire line using the same frequency band, it is required to sufficiently suppress the echo. The use of a conventional adaptation method may take a long time to train the echo canceler. Fast training can be achieved by initializing the coefficients of the echo canceler with an estimate of the impulse response of the echo path. In this lett...

Learning the basic concepts required to understand magnetic resonance (MR) imaging is a straightforward process. Although the individual concepts are simple, there are many concepts to learn and retain simultaneously; this situation may give the illusion that learning the physics of MR imaging is complicated. It is important for the radiologist who interprets MR images to understand the methods...