Wireless sound transmission system and method

Abstract

A system for providing sound to at least one user, having at least one audio signal source for providing audio signals; a transmission unit with a digital transmitter for wirelessly transmitting the audio signals as data packets; at least one receiver unit with at least one digital receiver for reception of the audio signals from the transmission unit; a mechanism for stimulating the hearing of the user(s) according to audio signals supplied from the receiver unit. The transmission unit transmits each data packet in a separate slot of a TDMA frame at a different frequency in a frequency hopping sequence, in at least some of the slots, the audio signals are transmitted as audio data packets, the same audio packet being transmitted at least twice in the same TDMA frame without expecting acknowledgement, and the TDMA frames being structured for unidirectional broadcast transmission of the audio data packets.

What is claimed is: 
     
       1. A system for providing sound to at least one user, comprising:
 at least one audio signal source for providing audio signals; 
 a transmission unit comprising a digital transmitter for applying a digital modulation scheme in order configured to transmit the audio signals as data packets from the audio signal source via a wireless digital audio link; 
 at least one receiver unit for reception of configured to receive audio signals from the transmission unit via the digital audio link, comprising at least one digital receiver; 
 means for stimulating hearing of at least one user according to audio signals supplied from the receiver unit;
 wherein the transmission unit is adapted configured to transmit each data packet in a separate slot of a TDMA frame at a different frequency according to a frequency hopping sequence, 
 wherein, in at least some of the slots, the audio signals are to be transmitted as audio data packets, wherein a same audio packet is to be transmitted at least twice in a same TDMA frame, without expecting acknowledgement messages from the at least one receiver unit, 
 wherein the TDMA frames are structured for unidirectional broadcast transmission of the audio data packets, without individually addressing the at least one receiver unit, and 
 wherein each audio data packet comprises a start frame delimiter, audio data and a frame check sequence, and wherein each digital receiver of the at least one receiver unit is adapted configured to verify each received data packet by using the frame check sequence and to use the audio data of the first verified version of each data packet as the signal to be supplied to the stimulation means while not using the audio data of other versions. 
 
 
     
     
       2. The system of  claim 1 , wherein the same audio packet is to be transmitted at least twice in subsequent slots. 
     
     
       3. The system of  claim 1 , wherein each receiver of the at least one receiver unit is adapted to sleep at least during times when no data packets are to be expected. 
     
     
       4. The system of  claim 3 , wherein each receiver of the at least one receiver unit is adapted to wake up a given guard time period before expected arrival of an audio packet different from the previous audio packet. 
     
     
       5. The system of  claim 4 , wherein each receiver of the at least one receiver unit is adapted to wake up at a given guard time period before expected arrival of the repetition of the previous audio packet, if a start frame delimiter has not been received or if the previous audio packet could not be verified. 
     
     
       6. The system of  claim 5 , wherein each receiver of the at least one receiver unit is adapted to go to sleep again after a given timeout period after an expected end of transmission of the audio packet, if no audio packet has been received. 
     
     
       7. The system of  claim 6 , wherein each receiver is adapted to go to sleep again after a given timeout period after an expected end of transmission of the start frame delimiter of the audio packet, if a start frame delimiter has not been received. 
     
     
       8. The system of  claim 1 , wherein, in a first slot of each frame, a beacon packet is to be transmitted which contains information for hopping frequency synchronization. 
     
     
       9. A system for providing sound to at least one user, the system comprising:
 at least onean audio signal source for providing audio signals; 
 a transmission unit comprising a digital transmitter for applying a digital modulation scheme in order configured to transmit the audio signals as data packets from the audio signal source via a wireless digital audio link; 
 at least onea receiver unit configured for reception of audio signalsthe data packets from the transmission unit via the digital audio link, comprising at least onewherein the receiver unit includes a digital receiver; 
 means for stimulating hearing of at least one providing at least portions of the audio signals to a user according to audio signals supplied from the receiver unit;,
 wherein the transmission unit is adapted to configured to transmit each data packet in a separate slot of a TDMA time-slotted frame at a different frequency according to a frequency hopping sequence, 
 wherein, in at least some of the slots, the audio signals data packets are to be transmitted as audio data packets, and  
 wherein a same each audio data packet is to be transmitted at least twice in a the same TDMA time-slotted frame, without expecting acknowledgement messages from the at least one receiverunit, 
 
 wherein, in a first slot of each frame, a beacon packet to be transmitted is provided which contains data necessary for synchronizing the network, and 
 wherein each receiver of the at least one receiver unit is adapted to wake up a given guard time period before expected arrival of the beacon packet of certain ones of the frames, while sleeping during expected transmission of the beacon packet of the other frames. 
 
     
     
       10. The system of  claim 9 , wherein each receiver of the at least one the receiver unit is adapted to wake up at a given guard time period before expected arrival of beacon packets of frames having a sequence number which fulfills a given condition with regard to an address of the respective receiver unit having a sequence number which fulfills a given condition with regard to periodicity. 
     
     
       11. The system of  claim 10 , wherein the at least one receiver unit comprise is a first receiver unit and the system further comprises a plurality of receiver units, and wherein the transmission unit is adapted to send a message to a specific one of the receiver units by including the message into the beacon packet of a frame having a sequence number for which the given condition is fulfilled with regard to an address of the a respective receiver unit. 
     
     
       12. A system for providing sound to at least one user, comprising:
 at least one audio signal source for providing audio signals;   a transmission unit comprising a digital transmitter for applying a digital modulation scheme in order to transmit the audio signals as data packets from the audio signal source via a wireless digital audio link;   at least one receiver unit for reception of audio signals from the transmission unit via the digital audio link, comprising at least one digital receiver;   means for stimulating hearing of at least one user according to audio signals supplied from the receiver unit;   wherein the transmission unit is adapted to transmit each data packet in a separate slot of a TDMA frame at a different frequency according to a frequency hopping sequence,   wherein, in at least some of the slots, the audio signals are to be transmitted as audio data packets, wherein a same audio packet is to be transmitted at least twice in a same TDMA frame, without expecting acknowledgement messages from the at least one receiver unit,   wherein, in a first slot of each frame, a beacon packet to be transmitted is provided which contains data necessary for synchronizing the network, and   wherein the at least one receiver unit comprise a plurality of receiver units, and wherein each receiver unit is adapted to wake up at a given guard time period before expected arrival of the beacon packet of frames having a sequence number fulfilling a certain global condition, in order to have all receiver units periodically listen to a same beacon packet.   
     
     
       13. The system of  claim 8 , wherein the transmission unit is adapted to receive in a second slot of each frame a control data packet from the receiver units requested by the transmission unit. 
     
     
       14. The system of  claim 8 , wherein a first slot of each frame is for multiplexing a beacon packet to be sent by the transmission unit and a control data packet to be received from the at least one receiver unit as requested by the transmission unit. 
     
     
       15. A system for providing sound to at least one user, comprising:
 at least one audio signal source for providing audio signals;   a transmission unit comprising a digital transmitter for applying a digital modulation scheme in order to transmit the audio signals as data packets from the audio signal source via a wireless digital audio link;   at least one receiver unit for reception of audio signals from the transmission unit via the digital audio link, comprising at least one digital receiver;   means for stimulating hearing of at least one user according to audio signals supplied from the receiver unit;   wherein the transmission unit is adapted to transmit each data packet in a separate slot of a TDMA frame at a different frequency according to a frequency hopping sequence,   wherein, in at least some of the slots, the audio signals are to be transmitted as audio data packets, wherein a same audio packet is to be transmitted at least twice in a same TDMA frame, without expecting acknowledgement messages from the at least one receiver unit,   wherein, in a first slot of each frame, a beacon packet to be transmitted is provided which contains data necessary for synchronizing the network, and   wherein the at least one receiver unit comprise a plurality of receiver units, and wherein each beacon packet includes at least one item of information relevant for an audio stream from the group of items comprising a description of encoding format, a description of audio content, a gain parameter, surrounding noise level; information relevant for multi-talker network operation, and control data for all or a specific one of the receiver units.   
     
     
       16. The system of  claim 1 , wherein the transmission unit is adapted to encode the audio data using ADPCM. 
     
     
       17. The system of  claim 1 , wherein the audio signal source is a microphone arrangement integrated into or connected to the transmission unit for capturing a speaker's voice. 
     
     
       18. The system of  claim 17 , wherein the transmission unit comprises an audio signal processing unit for processing the audio signals captured by the microphone arrangement prior to being transmitted. 
     
     
       19. The system of  claim 1 , wherein the transmission unit is adapted to establish the digital audio link at a carrier frequency in a 2.4 GHz ISM band. 
     
     
       20. The system of  claim 1 , wherein the transmission unit is adapted to be connected to an external audio device from the group of external audio devices comprising a mobile phone, an FM radio, a music player, a telephone and a TV device, as the audio signal source. 
     
     
       21. The system of  claim 1 , wherein the transmission unit is adapted to be connected via a digital audio link to an external transmission unit comprising a microphone for capturing a speaker's voice as the audio signal source. 
     
     
       22. The system of  claim 1 , wherein the at least one receiver unit comprise a plurality of receiver units, and wherein at least one of the receiver units is connected to or integrated into an ear-worn device, comprising the stimulation means. 
     
     
       23. The system of  claim 1 , wherein the at least one receiver unit comprise a plurality of receiver units, and wherein at least one of the receiver units is a neck-worn device comprising a transmitter for transmitting audio signals via an inductive link to an ear-worn device, comprising the stimulation means. 
     
     
       24. The system of  claim 1 , wherein the at least one receiver unit comprise a plurality of receiver units, and wherein the at least one receiver unit is connected to or integrated within at least one audience loudspeaker serving as the stimulation means. 
     
     
       25. A system for providing sound to at least one user, comprising:
 at least one audio signal source for providing audio signals;   a transmission unit comprising a digital transmitter for applying a digital modulation scheme in order to transmit the audio signals as data packets from the audio signal source via a wireless digital audio link;   at least one receiver unit for reception of audio signals from the transmission unit via the digital audio link, comprising at least one digital receiver;   means for stimulating hearing of at least one user according to audio signals supplied from the receiver unit;   wherein the transmission unit is adapted to transmit each data packet in a separate slot of a TDMA frame at a different frequency according to a frequency hopping sequence,   wherein in at least some of the slots, the audio signals are to be transmitted as audio data packets, wherein a same audio packet is to be transmitted at least twice in a same TDMA frame, without expecting acknowledgement messages from the at least one receiver unit,   wherein the TDMA frames are structured for unidirectional broadcast transmission of the audio data packets, without individually addressing the at least one receiver unit, and   wherein the at least one receiver unit comprise a plurality of receiver units, and wherein at least one of the receiver units is a neck-worn device comprising a transmitter for transmitting audio signals via an inductive link to an ear-worn device, comprising the stimulation means, and   wherein the at least one receiver unit comprise a plurality of receiver units, wherein each receiver unit comprises at least two digital receivers, each being connected to a common processing unit and an antenna and including a demodulator and a buffer, wherein each receiver is for receiving, verifying and buffering each of the audio data packets, wherein each receiver unit is adapted to send an interrupt request from at least one of the receivers to the processing unit to indicate when a packet has been received, and wherein the processing unit is adapted to read an audio data packet from a buffer of one of the receivers and, if the packet has been correctly received by that receiver, to flush the buffer of the other receivers and, if the packet has not been correctly received by that receiver, to read the audio data packet from the buffer of another one of the receivers.   
     
     
       26. A method for providing sound, the method comprising:
 transmitting an audio signal as audio data packets from a transmission unit via a wireless digital audio link;   receiving, at a receiver unit, the audio data packets from the transmission unit via the digital audio link,
 wherein the receiver unit includes a digital receiver, 
 wherein the transmission unit transmits each audio data packet twice in separate slots of a time-slotted frame at different frequencies according to a frequency hopping sequence, and 
 wherein transmissions of the twice transmitted audio data packets are executed unconditionally, irrespective of whether the receiver unit has correctly received one of the transmissions of the audio data packets. 
   
     
     
       27. The method of claim 26, wherein each frame comprises a start frame delimiter, the two audio data packets, and a frame check sequence, and wherein the digital receiver of the receiver unit verifies each received data packet by using a frame check sequence. 
     
     
       28. The method of claim 26, wherein the receiver unit is electronically coupled to or integrated in a hearing aid, headphone, or earphone. 
     
     
       29. A method for providing sound, the method comprising:
 receiving an audio signal;   converting the audio signal to digital audio packets;   transmitting wirelessly the digital audio packets to a receiver unit,
 wherein the transmitting further includes transmitting a first digital audio packet on a first frequency in a first time slot of a time-slotted frame, 
 wherein the transmitting further includes transmitting a second digital audio packet on a second frequency in a second time slot of the time-slotted frame, and 
 wherein the first digital audio packet and the second digital audio packet include the same audio information and are transmitted in subsequent slots of the time-slotted frame. 
   
     
     
       30. The method of claim 29, the method further comprising:
 determining an expected arrival time when the first digital audio packet is expected to arrive;   determining a time when the receiver unit will start listening by subtracting a guard period from the expected arrival time; and   in response to determining the time when the receiver unit will start listening, waking up the receiver unit to start listening at the time.   
     
     
       31. The method of claim 29, the method further comprising:
 determining that the first digital audio packet has been correctly received;   in response to determining the first digital audio packet has been correctly received, sleeping during the transmission of the second digital audio packet.   
     
     
       32. The method of claim 29, the method further comprising:
 in response to determining the first digital audio packet was not received, switching the receiver unit to receive the second digital audio packet on the second frequency and waiting for the second digital packet.   
     
     
       33. The method of claim 29, wherein the receiver unit is electronically coupled to or integrated into a hearing aid or headphone. 
     
     
       34. The method of claim 29, wherein the time-slotted frame includes a zero time slot, wherein the zero time slot includes a beacon packet, and wherein the beacon packet includes data for synchronizing. 
     
     
       35. A non-transitory computer-readable medium storing instructions, which when executed by a device, cause the device to perform operations for providing audio to multiple receivers, the operations comprising:
 receive an audio signal;   convert the audio signal to digital audio packets;   transmit wirelessly the digital audio packets to a receiver unit,
 wherein the transmitting further includes transmitting a first digital audio packet on a first frequency in a first time slot of a time-slotted frame, 
 wherein the transmitting further includes transmitting a second digital audio packet on a second frequency in a second time slot of the time-slotted frame, and 
 wherein the first digital audio packet and the second digital audio packet include the same audio information and are transmitted in subsequent slots of the time-slotted frame. 
   
     
     
       36. The non-transitory computer readable medium of claim 35, the operations further comprising:
 determine an expected arrival time when the first digital audio packet is expected to arrive;   determine a time when the receiver unit will start listening by subtracting a guard period from the expected arrival time; and   in response to determining the time when the receiver unit will start listening, wake up the receiver unit to start listening at the time.   
     
     
       37. The non-transitory computer readable medium of claim 35, the operations further comprising:
 determine that the first digital audio packet has been correctly received;   in response to determining the first digital audio packet has been correctly received, sleep during the transmission of the second digital audio packet.   
     
     
       38. The non-transitory computer readable medium of claim 35, the operations further comprising:
 in response to determining the first digital audio packet was not received, switch the receiver unit to receive the second digital audio packet on the second frequency and wait for the second digital packet.   
     
     
       39. The non-transitory computer readable medium of claim 35, wherein the receiver unit is electronically coupled to or integrated in a hearing aid, earphone, or headphone. 
     
     
       40. The method of claim 26, wherein the transmission unit transmits each audio data packet three times in separate slots of the time-slotted frame.