Hearing device without reference clock component
View Patent ↗A hearing device, in particular a hearing aid, occupies a small volume and has high data transmission speeds for wireless transmission. In order to avoid using large volume frequency-stable components, for this purpose, an oscillator unit with a free-running oscillator is used instead. A receiver receives a synchronization signal cyclically. This is correlated to a reference signal in a correlator, such that the arrival time of the synchronization signal can be defined exactly. The free-running oscillator is then retuned correspondingly.
1. A hearing device in a binaural hearing system in wireless communication with another hearing device in the binaural hearing system, said hearing device and said another hearing device using a synchronization signal to synchronize operation of the hearing device and said another hearing device, said hearing device comprising:
a signal processor that supplies a processor output for conversion into an audio output;
a receiver connected to the signal processor, said receiver receiving said synchronization signal;
an oscillator unit connected to the receiver to clock the receiver, said oscillator unit comprising a free-running oscillator; and
a correlation unit connected to the receiver that correlates a predetermined reference signal with the synchronization signal to obtain a correlation result, said free-running oscillator being connected to the correlation unit through switchable capacitors operated by said correlation result to tune the free-running oscillator.
2. A hearing device in a binaural hearing system in wireless communication with another hearing device in the binaural hearing system, said hearing device and said another hearing device using a synchronization signal to synchronize operation of the hearing device and said another hearing device, said hearing device comprising:
a signal processor that supplies a processor output for conversion into an audio output;
a receiver connected to the signal processor, said receiver receiving said synchronization signal;
an oscillator unit connected to the receiver to clock the receiver, said oscillator unit comprising a free-running oscillator;
a correlation unit connected to the receiver that correlates a predetermined reference signal with the synchronization signal to obtain a correlation result, said free-running oscillator being connected to the correlation unit and supplied with said correlation result to tune the free-running oscillator; and
said oscillator unit comprising a counter that generates a count between two synchronization signals, and a storage unit that stores frequency characteristics for said free-running oscillator respectively associated with different counts, and said free-running oscillator being tuned by selecting a frequency characteristic corresponding to said count.
3. A hearing device as claimed in claim 2 wherein said storage unit comprises a look-up table, and comprising switchable capacitors connected to said free-running oscillator, said switchable capacitors being selectively switched dependent on said count.
4. A hearing device in a binaural hearing system in wireless communication with another hearing device in the binaural hearing system, said hearing device and said another hearing device using a synchronization signal comprising a cyclically recurring burst to synchronize operation of the hearing device and said another hearing device, said hearing device comprising:
a signal processor that supplies a processor output for conversion into an audio output;
a digital receiver connected to the signal processor, said receiver receiving said synchronization signal comprising said cyclically recurring burst;
an oscillator unit connected to the receiver to clock the receiver, said oscillator unit comprising a free-running oscillator; and
a digital correlation unit connected to the receiver that correlates a predetermined reference signal with the synchronization signal comprising said cyclically recurring burst to obtain a correlation result, said free-running oscillator being connected to the correlation unit and supplied with said correlation result to tune the free-running oscillator.
5. A hearing device as claimed in claim 4 comprising tuning said free-running oscillator with each cyclically recurring burst.
6. A hearing device as claimed in claim 4 wherein said burst is coded according to the Barker code.
7. A hearing device in a binaural hearing system in wireless communication with another hearing device in the binaural hearing system, said hearing device and said another hearing device using a synchronization signal comprising a cyclically recurring chirp to synchronize operation of the hearing device and said another hearing device, said hearing device comprising:
a signal processor that supplies a processor output for conversion into an audio output;
an analog receiver connected to the signal processor, said receiver receiving said synchronization signal comprising said cyclically recurring chirp;
an oscillator unit connected to the receiver to clock the receiver, said oscillator unit comprising a free-running oscillator; and
an analog correlation unit connected to the receiver that correlates a predetermined reference signal with the synchronization signal comprising said cyclically recurring chirp to obtain a correlation result, said free-running oscillator being connected to the correlation unit and supplied with said correlation result to tune the free-running oscillator.