公开(公告)号：US11452100B2

公开(公告)日：2022-09-20

申请号：US17253463

申请日：2019-07-03

Applicant: RTX A/S

Inventor： Jens Toftgaard Petersen ,  Flemming Mortensen

IPC: A63F13/235 ,  A63F13/327 ,  H03M13/09 ,  H03M13/31 ,  H04B7/04 ,  H04B7/12 ,  H04B17/345 ,  H04B17/373 ,  H04J1/04 ,  H04J1/16 ,  H04L1/00 ,  H04L1/08 ,  H04L5/00 ,  H04L43/0829 ,  H04L47/32 ,  H04L67/12 ,  H04L69/14 ,  H04W24/10 ,  H04W28/08 ,  H04W72/04 ,  H04W72/08 ,  H04W84/20 ,  H04W88/08 ,  H04W92/10

Abstract: A wireless communication method and protocol for wireless RF transmission of data, e.g. audio data, with low latency. The method involves a fixed part (FP) serving as synchronization master, and one or more portable parts (PP) being synchronization slaves. The FP performs scanning between a set of supported channels within one limited frequency band, such as within an ISM band. Further, the FP performs collecting measures of RF interference level on at least a plurality of the supported channels in response to the scanning, preferably using own interference level measurement and by collecting RSSI data from the PP for the supported channels. In response to these measures of RF interference level, the FP executes a selection algorithm for selecting and re-selecting first and second different frequencies for respective first and second duplex RF bearers from the set of supported channels to select the channels with least RF interference. Finally, the FP transmits, in one frame of such as 1 ms to 3 ms length, the same data packet on both of said first and second duplex RF bearer frequencies to the PP. This provides a roboust and low latency wireless interface suitable for Human Interface Devices and audio devices, e.g. for gaining equipment.

公开(公告)号：US11545164B2

公开(公告)日：2023-01-03

申请号：US16619039

申请日：2018-06-15

Applicant: RTX A/S

Inventor： Jens Toftgaard Petersen

IPC: G10L19/005 ,  G10L19/035 ,  G10L19/08

Abstract: An audio codec suitable for robust wireless transmission of high quality audio with low latency, still at a moderate bit rate. The encoding and decoding methods are based on ADPCM and in addition to the encoded output bits APM, additional data QB are included in output data blocks, namely data QB representing an internal value of the adaptive quantization ADQ of the ADPCM encoding algorithm, especially a scaling factor encoded and truncated to such as 8 bits. Further, output data blocks preferably include data CFB representing an internal value of the predictor PR of the ADPCM encoding algorithm, especially data CFB representing coefficients of a lattice prediction FIR filter which, truncated to such as 8 bits, can be sequentially included in output data blocks. These additional data QB, CFB regarding internal values of the ADPCM encoding algorithm can be utilized at the encoder side to increase robustness against loss of data blocks in wireless transmission. Especially, the decoding algorithm may comprise comparing its current internal ADPCM decoding values corresponding to the received internal values QB, CFB from the encoder, and in case there is a difference, the decoder can adapt or overwrite its internal values to the ones received QB, CFB. This helps to ensure fast recovery after lost data blocks, thereby ensuring robustness against artefacts in the reconstructed signal, e.g. clicks in case of audio.