US-20260128827-A1 - WIRELESS COMMUNICATION DEVICE WITH PACKET-LEVEL ADAPTIVE BITRATE CONTROL AND ASSOCIATED WIRELESS COMMUNICATION METHOD

US20260128827A1US 20260128827 A1US20260128827 A1US 20260128827A1US-20260128827-A1

Abstract

A wireless communication device includes an encoder circuit and a wireless communication circuit. The encoder circuit encodes the same input data to generate and output frames with different encoding quality. The wireless communication circuit receives the frames from the encoder circuit, and transmits at least one frame selected from the frames to another wireless communication device via a wireless link.

Inventors

Ming-Yi Hsieh

Assignees

AIROHA TECHNOLOGY CORP.

Dates

Publication Date: 20260507
Application Date: 20250605

Claims (20)

1 . A wireless communication device comprising: an encoder circuit, arranged to encode a same input data to generate and output a plurality of frames with different encoding quality; and a wireless communication circuit, arranged to receive the plurality of frames from the encoder circuit, and transmit at least one frame selected from the plurality of frames to another wireless communication device via a wireless link.
2 . The wireless communication device of claim 1 , wherein the plurality of frames comprise a first frame with first encoding quality and a second frame with second encoding quality that is higher than the first encoding quality, and the at least one frame comprises the first frame.
3 . The wireless communication device of claim 2 , wherein the wireless communication circuit is further arranged to receive a negative-acknowledgment (NAK) indicating that the first frame is not received by the another wireless communication device, and retransmit the first frame in retransmission time slots in response to the NAK; and the at least one frame does not comprise the second frame.
4 . The wireless communication device of claim 2 , wherein the wireless communication circuit is further arranged to receive an acknowledgment (ACK) indicating that the first frame is received by the another wireless communication device; and the at least one frame further comprise the second frame, where the wireless communication circuit transmits the second frame in retransmission time slots in response to the ACK.
5 . The wireless communication device of claim 4 , wherein the wireless communication circuit comprises: a plurality of separate physical layer (PHY) circuits, comprising: a first PHY circuit, arranged to transmit the first frame; and a second PHY circuit, arranged to transmit the second frame.
6 . The wireless communication device of claim 2 , wherein the wireless communication circuit is further arranged to receive a flag, and determine whether to skip transmission of the second frame in retransmission time slots according to a setting of the flag.
7 . The wireless communication device of claim 2 , wherein the first frame is a lossy compressed frame.
8 . The wireless communication device of claim 7 , wherein the second frame is a lossy compressed frame.
9 . The wireless communication device of claim 7 , wherein the second frame is a lossless compressed frame.
10 . The wireless communication device of claim 9 , wherein the lossless compressed frame comprises a plurality of subframes, and the subframes comprise an uncompressed subframe and a lossless compressed subframe.
11 . The wireless communication device of claim 7 , wherein the second frame is an uncompressed frame.
12 . The wireless communication device of claim 1 , wherein the same input data is an uncompressed audio data.
13 . The wireless communication device of claim 1 , wherein the wireless link is a Bluetooth (BT) link.
14 . The wireless communication device of claim 13 , wherein the BT link is a Low Energy (LE) Isochronous (ISO) Channel.
15 . The wireless communication device of claim 13 , wherein the wireless communication device is a dongle, a phone, or a laptop, and the another wireless communication device is a headphone, a speaker, or an earbud.
16 . A wireless communication method comprising: performing an encoding operation upon a same input data to generate and output a plurality of frames with different encoding quality; and transmitting at least one frame selected from the plurality of frames to a wireless communication device via a wireless link.
17 . The wireless communication method of claim 16 , wherein the plurality of frames comprise a first frame with first encoding quality and a second frame with second encoding quality that is higher than the first encoding quality, and the at least one frame comprises the first frame.
18 . The wireless communication method of claim 17 , further comprising: receiving a negative-acknowledgment (NAK) indicating that the first frame is not received by the wireless communication device; retransmitting the first frame in retransmission time slots in response to the NAK; wherein the at least one frame does not comprise the second frame.
19 . The wireless communication method of claim 17 , further comprising: receiving an acknowledgment (ACK) indicating that the first frame is received by the wireless communication device; wherein the at least one frame further comprise the second frame, and the second frame is transmitted in retransmission time slots in response to the ACK.
20 . The wireless communication method of claim 16 , wherein the first frame is a lossy compressed frame; and the second frame is a lossy compressed frame, a lossless compressed frame, or an uncompressed frame.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63/717,290, filed on November 7, 2024. The content of the application is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communications, and more particularly, to a wireless communication device with packet-level adaptive bitrate (ABR) control and an associated wireless communication method. 2. Description of the Prior Art Lossless audio is the best form of audio as it has no drop in quality, and there is no quality degradation in the compression of the audio file. The lossless audio that the user hears is as good as the source material. However, lossless audio playback requests a high data rate for transmission of a lossless compressed audio bitstream from a source device to a sink device. To meet the high data rate requirement, the physical layer (PHY) throughput must be high, which requests a wider PHY bandwidth. However, it is difficult to maintain stability of audio under a wide PHY bandwidth in a noisy environment, which causes audio frame dropped and quality degradation on lossless audio playback. Furthermore, throughput of transportation between the source device and the sink device may be limited and may change with time. Hence, a rate control scheme is generally employed to ensure that the bitstream is sent/received on time. For example, a typical rate estimation (RE) mechanism may be implemented on either the source side or the sink side. There is a response delay for reporting a rate estimation result of the RE mechanism to an encoder of the source device. In addition, there is a processing delay for the source-side encoder to actually change its output bitrate. Consider a case where throughput of transportation between the source device and the sink device changes to a lower level, causing an increase of the audio packet drop rate. Before the bitrate is actually reduced by the source-side encoder through the typical RE-based rate control scheme, the sink device may suffer audio dropout. Particularly, the bitrate control delay (which may include the response delay and the processing delay) is a big issue for low-latency uncompressed/lossless audio applications. Thus, there is a need for an innovative ABR control scheme which does not use the typical RE mechanism and can meet requirements of low-latency uncompressed/lossless audio applications. SUMMARY OF THE INVENTION One of the objectives of the claimed invention is to provide a wireless communication device with packet-level ABR control and an associated wireless communication method. According to a first aspect of the present invention, an exemplary wireless communication device is disclosed. The exemplary wireless communication device includes an encoder circuit and a wireless communication circuit. The encoder circuit is arranged to encode a same input data to generate and output a plurality of frames with different encoding quality. The wireless communication circuit is arranged to receive the plurality of frames from the encoder circuit, and transmit at least one frame selected from the plurality of frames to another wireless communication device via a wireless link. According to a second aspect of the present invention, an exemplary wireless communication method is disclosed. The exemplary wireless communication method includes: performing an encoding operation upon a same input data to generate and output a plurality of frames with different encoding quality; and transmitting at least one frame selected from the plurality of frames to a wireless communication device via a wireless link. These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating an audio codec (encoder-decoder) model with the proposed packet-level ABR control according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a wireless communication device using the proposed packet-level ABR control scheme according to an embodiment of the present invention. FIG. 3 is a flowchart illustrating a packet-level ABR control method according to an embodiment of the present invention. FIG. 4 is a diagram illustrating retransmission slots available between transmissions of two frames. FIG. 5 is a diagram illustrating a scenario in which retransmission slots are used for retransmission of a previously transmitted frame with low quality/bitrate. FIG. 6 is a diagram illustrating a scenario in which retransmission slots are reused for transmission of a not-yet-transmitted frame with high quality/bitrate. DETAILED DESCRIPTION Certain terms are used throughout the following description and claims, which refer to particu