Turbo Encoder Tail-Biting State Determination

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Solution Overview

Problem

Turbo encoders face inefficiencies due to the time-consuming and power-consuming process of determining the last and final states for tail-biting, which affects the transfer rate and error protection in communication systems.

Innovation Solution

A method and apparatus that utilize the periodicity of powers of a state matrix to efficiently determine the last state and final state of a turbo encoder, allowing for parallel operations to reduce calculation time and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the conventional tail-biting method is used to determine the last state and final state of the turbo encoder, then the error protection capability is maintained, but the processing time and power consumption increase significantly

Engineering Contradiction:

Improveerror protection capabilityVSAvoidprocessing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent pre-calculates and stores the relationship between initial states and corresponding last states in a look-up table during the encoder design phase. This preliminary action allows the decoder to quickly retrieve the last state information without performing time-consuming calculations during actual decoding operations, thus reducing processing time while maintaining error protection capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a simplified model of the encoder's state transitions and stores the essential state information in a look-up table. Instead of replicating the full encoder computation process during decoding, the system uses this copied state information to determine the last state efficiently, reducing computational complexity and power consumption while preserving the error protection functionality

Inventive Principle:

Principle #26Copying

2Reliability

If the conventional tail-biting method is used to determine the last state and final state of the turbo encoder, then the error protection capability is maintained, but the power consumption increases

Engineering Contradiction:

Improveerror protection capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent performs the computationally intensive state calculation work in advance during the encoder design phase and stores the results in a look-up table. This preliminary action shifts the power consumption to the design phase rather than the operational phase, significantly reducing power consumption during actual encoding and decoding operations while maintaining error protection capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a compressed representation of the encoder state transitions and stores it in a look-up table. This copied information allows the system to retrieve state information without performing full encoder computations during operation, thereby reducing power consumption while preserving the error protection functionality

Inventive Principle:

Principle #26Copying

3Stability of the object's composition

If tail bits are appended to data bits to obtain code blocks, then the encoder can start and end at the all-zero state, but the transfer rate is reduced due to tail bit termination

Engineering Contradiction:

Improveencoder state stabilityVSAvoidtransfer rate

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent pre-determines the relationship between initial states and last states and stores it in a look-up table. This allows the system to use any valid state as the initial state rather than being constrained to the all-zero state, eliminating the need for tail bits and improving transfer rate while maintaining encoder state stability through the stored state relationships

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of forcing the encoder to return to the all-zero state by appending tail bits, the patent inverts the approach by allowing the encoder to end at any state and using the look-up table to determine the corresponding initial state. This inversion eliminates the need for tail bits and improves transfer rate while maintaining the mathematical relationship between initial and final states

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS7392462B2Method of finding a last state in tail-biting for turbo encoder and apparatus using the same

Publication Date: 2008.06.24 SAMSUNG ELECTRONICS CO LTD

AI summary

Encoding inputs corresponding to a set of powers of state matrix is added. Powers of state matrix have period T. The set of the powers of the state matrix has an identical state matrix value. One of the powers of the state matrix is multiplied by input matrix and the added encoding inputs. Multiplied results are added so as to find last state of the turbo encoder. The last state corresponds to encoding state of the turbo encoder when the turbo encoding is started at zero state. Final state of the turbo encoder is found using the last state. The final state is identical to initial state of the turbo encoder, and corresponds to encoding state of the turbo encoder when turbo encoding is started with the initial state. Encoding inputs are encoded using the final state.