Rtx A/s

Jens Toftgaard Petersen

Peter Mariager

Rune Strøm Jensen

Henrik Hvedegaard

Lars Hansen

Morten Laursen

Flemming Mortensen

Rune Strom Jensen

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.

Audio signal encoding and decoding

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.

Low latency wireless protocol for audio and gaming

A method for programming a processor in a communication device arranged for communication according to a DECT/CAT-iq protocol. The method has three steps: 1) A high level language program code is provided, the program code being arranged to influence a function of the communication device. E.g. this program code may be an application program code. 2) The program code is then interpreted into a corresponding machine language code arranged for execution on the processor in the communication device. 3) Finally, this machine language is executed by the processor in the communication device. This method allows a user to program the DECT/CAT-iq device in a high level language without the need for a compiler to compile the high level language program into a processor specific machine code. Preferably, the interpreting of the high level program code is performed by the processor (P) in the communication device. Especially, the processor (P) may be programmed to operate as a virtual central processing unit (VCPU).

Programming of a DECT/CAT-iq communication device

Wireless base station device for handling wireless communication, e.g. DECT, between a plurality of associated wireless terminals and an IP network. The base station device has a radio transceiver, a network interface, and a processor with communication application and a communication session management software. The communication session management is arranged to control a communication session with an associated wireless terminal (upper layer management), while wireless communication with said associated wireless terminal involved with said communication session (lower layer) is handled by another base station device. Thus, the base station can manage separate operation of its upper and lower layer, thereby enabling e.g. hand-over of a session to and from other base stations. This allows self contained single casing base station devices to operate in a network without the need for at central server, and still such network is easy to extend by adding base stations.

Scalable wireless multicell VoIP architecture

A cell, preferably a stand-alone device, arranged for wireless communication with a plurality of other cells in a communication network, e.g. a TDMA network such as a DECT based network. The cell includes a processor performing a selection algorithm which selects a reference cell among other cells. The selection algorithm bases the selection on a wireless signal, e.g. an RF signal, received from at least two other cells. Further, the cell includes a wireless receiver for receiving a first wireless signal, e.g. an RF signal, from the reference cell with time synchronization information for the reference cell. The cell includes a wireless transmitter which transmits time synchronization information for the cell itself represented in a second wireless signal, e.g. and RF signal. The selection algorithm selects the reference cell based on transmission link quality measurements and cell path information received from a number of cell candidates. The cell preferably also itself transmits cell path information, e.g. at regular intervals. Preferably, the cell can generate a random number and transmit it in wireless form as its cell identity code. A network of such cells can be self-configured, i.e. no manual action is required. Further, it allows changes in network topology, e.g. change of position of one or more cells, since each cell can automatically adapt to a new topology and select the most reliable reference cell to synchronize to.

Growing community of inventors

Svenstrup J, Denmark

Jens Toftgaard Petersen