Adaptive hybrid ARQ using turbo code structure
AssigneeMotorola, Inc.
InventorsAmitava Ghosh, Brian K. Classon, Mark C. Cudak, Louay Jalloul
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Abstract
A generic structure of Hybrid ARQ using Turbo Codes is provided which requires the function of a) channel coding, b) redundancy selection, c) buffering and max-ratio diversity combining, d) channel decoding, e) error detection and f) sending back an acknowledgement to the transmitter. The functions (a) and (b) are performed at the transmitter while functions (c) to (f) are performed at the receiver. The initial code rate can be explicitly communicated to the receiver or blindly detected.
Claims19
A method for transmitting data packets, the method comprising the steps of:
- receiving an incoming data packet;
- determining an initial turbo code rate based on a channel condition;
- turbo encoding the data packet to produce encoded bits comprising a plurality of systematic bits and a plurality of parity bits;
- transmitting a first portion of the encoded bits based on the initial turbo code rate;
- determining if an acknowledgment has been received for the transmitted first portion;
- and
- based on the acknowledgment and the initial turbo code rate, transmitting a second portion of the encoded bits.
A method for receiving data packets, the method comprising the steps of:
- receiving a portion of an encoded data packet;
- determining the content of information and parity symbols in the received portion based on an initial code rate for a first received portion of the encoded data packet;
- self-decoding the received portion;
- determining whether the self-decoding successfully decoded the received portion;
- when the self-decoding of the received portion is not successful, combining the received portion of the encoded data packet with a previously combined portion of the encoded data packet to produce a new combined portion;
- storing the new combined portion;
- joint turbo decoding the new combined portion to produce decoded bits;
- and
- acknowledging if no error is present in the decoded bits.
Dependencies are inferred from the claim text.