公开(公告)号：SG124304A1

公开(公告)日：2006-08-30

申请号：SG200500298

申请日：2005-01-20

Applicant: ST MICROELECTRONICS ASIA

Inventor： MURALIDHAR KARTHIK ,  WAH OH SER

Abstract: The present invention utilizes an adaptive channel estimation unit 29 in a rake finger 12 of a rake receiver 10 of a MSR. The adaptive channel estimation unit 29 provides channel estimates 28 by processing de-spread pilot signals 18 via an optimum averaging length, determined by an adaptive averaging unit in the adaptive channel estimation unit 29. The adaptive channel estimation unit 29 further comprises a channel estimation unit 30 and an adaptive averaging unit 32. The adaptive channel estimation unit 29 first calculates noisy channel estimates 31 and then adaptively determines the optimum averaging length panies the abstract.

公开(公告)号：SG139731A1

公开(公告)日：2008-02-29

申请号：SG2007058860

申请日：2007-08-10

Applicant: ST MICROELECTRONICS ASIA

Inventor： MURALIDHAR KARTHIK ,  KRISHNA ANOOP KUMAR

Abstract: A Yule-Walker based, low-complexity voice activity detector (VAD) is disclosed. An input signal is typically noisy speech (i.e., corrupted with, for example, babble noise). In one embodiment, a first initialization stage of the VAD computes an occurrence of a silent period within the input signal and the AR parameters. The VAD could accordingly compute a tentative adaptive threshold and output hypothesis H 1 (which means speech is present) during this stage. During the second initialization stage, the VAD generally builds a database of associated values and computes the adaptive threshold accordingly. The second initialization stage could also output tentative VAD decisions based on the tentative threshold computed in the first initialization stage. Finally, the VAD periodically retrains or updates AR parameters, threshold values and/or the database and outputs VAD decisions accordingly.