Invented by Jing Jiang, Joseph Binamira Soriaga, Tingfang JI, Kambiz Azarian Yazdi, Krishna Kiran Mukkavilli, John Edward Smee, Qualcomm Inc
The Qualcomm Inc invention works as follows
Methods and systems are described for fountain-based hybrid automatic repeat requests (HARD) to ensure reliable communication with low latency. Wireless devices may transmit data blocks based on low-latency operation modes. The device can then transmit multiple redundancy versions before determining if an acknowledgement has been received. In some cases, the ACK can be an augmented ACK. This ACK is based on how many redundancy versions were received before successfully decoding the block and may also include an extra resource request. The device may, in some cases, select an updated modulation scheme based on the augmented ACK. The device may, in some cases, increase the number of frequencies (e.g. component carriers) that are used for transmission based upon the augmented ACK.
Background for Fountain Harq for reliable low-latency communication
Field of Disclosure
The following is a general description of wireless communication and, more specifically, fountain hybrid automatic repetition request (HARQ) to ensure reliable low-latency communication.
Description of Related Art.
Wireless communications systems provide a wide range of communication content, including voice, video and packet data. They also support messaging, broadcasting, and other types of communication. These systems can be multiple-access systems that support communication with multiple users through sharing system resources (e.g. time, frequency and power). These systems can include time division multiple-access (TDMA), frequency division multi-access (FDMA), and code division multiple-access (CDMA).
By way if example, a wireless multi-access communication system may include multiple base stations that support communication simultaneously for multiple communication devices. These communication devices may also be known as user equipments (UEs). A base station can communicate with communication devices using downlink channels, e.g. for transmissions between a base and UE, or uplink channels, e.g. for transmissions of UEs to a station. In some cases, UEs can also directly communicate with each other.
In some cases, wireless devices may send HARQ Feedback such as an acknowledgment (ACK) of a negative acknowledgement (NACK), to indicate if a transmission has been correctly received. The transmitter may retransmit a message if it receives a negative acknowledgment (NACK) to ensure that the data is delivered successfully. The HARQ may be a lengthy process due to the time it takes to decode the message and the time required for the NACK. This can cause a delay in the communication between devices. It may also affect the reliability and data rate of the wireless connection.
The present disclosure can relate to wireless communication systems in general, and to systems, methods or apparatuses that are associated with fountain hybrid automatic repetition request (HARQ) to ensure reliable low-latency communication. Wireless devices may transmit data blocks based on low latency operation modes. The device can then transmit multiple redundancy versions before determining if an acknowledgement has been received. In some cases, the ACK can be an augmented ACK. This ACK is based on how many redundancy versions were received before successfully decoding the block and may also include a resource request. The device may, in some cases, select an updated modulation scheme and coding scheme based on the augmented ACK. The device may, in some cases, increase the number of frequencies (e.g. component carriers) that are used for transmission based upon the augmented ACK.
A method of wireless communications is described. The method can include transmitting a block of data using a first resource set based on a mode of low latency operation, and transmitting a plurality of redundancy copies of the block using a secondary set of resources based upon the low latency mode.
The invention is a wireless communication apparatus. The apparatus can include means for transmitting a block of data using a first resource set based on a mode of operation with low latency, and means for sending a number redundancy copies of the block using a secondary set of resources based upon the low-latency mode of operation, the number redundancy copies of the block being sent before determining if an ACK for the block is received.
A further wireless communication apparatus is described. The apparatus can include a processor and memory in electronic communications with the processor. Instructions stored in the memory are executable by processor and enable the processor to transmit a block of data using a first resource set based on a mode of low latency operation, and to transmit a number redundancy copies of the block using a second resource set based upon the low latency mode.
The invention is a non-transitory, computer-readable medium that stores code for wireless communications. The code can include instructions executable for transmitting a datablock using a first resource set based on a high latency operation mode and transmitting a number redundancy version of the same data block with a second resource set based on a high latency operation mode.
Some examples of the methods, apparatuses or non-transitory computers-readable media described above can further include selecting an MCS initial based at the least in part on channel conditions or the size of the block, and transmitting the block based on the MCS initial. In some cases, the ACK may be an augmented ACK based, at least partially, on the number and type of redundancy versions, with an additional resource request.
Some examples of the methods, apparatuses or non-transitory computers-readable media described above can further include receiving an ACK via a reduced symbol-duration uplink (UL), based on a low-latency operational mode. Alternatively, or in addition to this, some examples could include receiving a certain number of NACKs corresponding with the number of redundancy version on the reduced symbol length UL control channel.
Some examples of the methods, apparatuses or non-transitory computers-readable medium described may also include refraining to transmit an additional redundancy copy of the data block based upon the ACK. In some cases, the low-latency mode may also include a shorter transmission time interval.
In some examples, the second group of resources are contiguous with the first in terms of time. Some examples can also or alternatively include transmitting information via a reduced symbol-duration downlink (DL), based on low latency operation mode.
A method of wireless communications is described. The method can include receiving a block of data using a set first of resources in a low-latency mode, computing first LLRs, determining a set first of decoded bit from the first LLRs do not pass the CRC. Receiving a number redundancy version of the block in the low-latency mode using a set second of resources before transmitting a “NACK”, computing an updated LLRs set for the block of data based upon the number redundancy.
The apparatus is described as a wireless communication device. The apparatus can include means to receive a datablock using a set first of resources based upon a low-latency operational mode. Means are also described for computing a set first of LLRs, determining a set first of decoded bit from the set first of LLRs do not pass a CRC. Means may be further described for receiving a set number of redundancy version of the block based upon the low-latency operational mode before transmitting a “NACK”, means
A further wireless communication apparatus is described. The apparatus can include a processor and memory in electronic communications with the processor. The instructions in the memory are executable by a processor to: receive a block of data using a set first of resources in a low-latency operational mode; determine that one set decoded from the first LLRs fails a CRC; receive a redundancy version of the block based in the low-latency operational mode before transmitting a “NACK”; receive a set number of redundancy copies of the
The invention is a non-transitory, computer-readable medium that stores code for wireless communications. The code can include instructions that are executable in order to receive a block of data using a set first of resources, compute a set first of LLRs, determine a set first of decoded bit from the set first of LLRs do not pass a CR, receive redundancy version of the block based upon the low latency operation mode using a set second of resources before transmitting a nack, receive the redundancy version of the block based upon the low latency mode using a number using a based using a based using a number using a number using a number using a number using a number using the second set using a number using the low latency using a number using the low latency using the low latency using the low latency using a number using the low latency using the a a a a a a number using a number using a a a a number, a NACK and a number,
In some examples, the methods, apparatuses or non-transitory computers-readable media described above include receiving the block of data using an initial MCS that is based, at least in part, on the channel condition or the size of the block. In some cases, the ACK can be an augmented ACK based in part at least on the number redundancy versions. It may also include an additional resource request.
Some examples of the methods, apparatuses or non-transitory computers-readable media described above can further include receiving a next data block by using an updated MCS based, at least in part, on the augmented ACK. In some cases, the request for additional resources is also or alternatively based on reliability metrics.