44results about How to "Suppress noise signal" patented technology

A method and a wearable communication system for personal face-to-face and wireless communications in high noise environments are provided. A noise cancellation device (NCD) operably coupled to a wireless coupling device (WCD) includes a speech acquisition unit, an audio signal processing unit, one or more loudspeakers, and a communication module. The NCD receives voice vibrations from user speech via a contact microphone and a second microphone and converts the voice vibrations into an audio signal. The NCD processes the audio signal to remove noise signals and enhance a speech signal contained in the audio signal. A loudspeaker emits the speech signal during face-to-face communication. The NCD transmits the speech signal to a communication device via the WCD and receives an external speech signal from the communication device during wireless communication. With the NCD, the signal intelligibility and signal-to-noise ratio can be improved, for example, from −10 dB to 20 dB.

The invention relates to a self-resonant array antenna for through-the-earth communication and an antenna unit. The array antenna comprises at least two antenna units; each antenna unit includes an alternating-current loop and an excitation loop; the alternating-current loop comprises a coil which is formed by at least one turn of electric conduction body and a capacitor module which is connected between two ends of the electric conduction body; the excitation loop comprises an electric conduction ring, wherein the electric conduction ring has an open end which is used for connecting a signal transmitting or receiving port of a communication system; the alternating-current loop and the excitation loop in the same antenna unit are in insulation and electromagnetic field coupling with each other; and the open ends of the excitation loops of the antenna units are in series connection, in parallel connection or in series-parallel connection. With the self-resonant array antenna of the invention adopted, the ability of the through-the-earth communication system to receive weak signals can be significantly improved, and therefore, the problem of short through-the-earth communication transmission distance can be solved.

Provided is a structure having an oriented piezoelectric polymer arranged into a cylindrical or columnar shape, wherein the oriented angle of the oriented piezoelectric polymer is 15-75 degrees with respect to the center axis of the structure, the piezoelectric polymer includes a crystal polymer of which the absolute value of piezoelectric constant d14 is 0.1-1000 pC / N when the oriented piezoelectric polymer has three orientation axes, and include a P body containing a crystal polymer of which the value of piezoelectric constant d14 is positive and an N body containing a crystal polymer of which the value of piezoelectric constant d14 is negative, and, when, in a part having a 1 cm length in the center axis of the structure, the mass of the P body in which the orientation axis is spirallywound in a Z twisting direction is defined as ZP, the mass of the P body in which the orientation axis is spirally wound in an S twisting direction is defined as SP, the mass of the N body in which the orientation axis is spirally wound in the Z twisting direction is defined as ZN, the mass of the N body in which the orientation axis is spirally wound in the S twisting direction is defined as SN,and, of (ZP+SN) and (SP+ZN), the smaller one is defined as T1 and the larger one is defined as T2, the value of T1 / T2 is 0 to 0.8. Also provided are a braided piezoelectric element and a fabric-like piezoelectric element each using the structure.