Time-Switched Preamble Generator for MIMO Channel Estimation

Solution Overview

Problem

MIMO communication systems face increased computational complexity in estimating channel coefficients as the number of transmit antennas grows, making it challenging to provide reliable channel estimates efficiently.

Innovation Solution

A time-switched preamble supplement generator is introduced, which provides a first permutation of preamble supplements during an initial time interval and subsequent mutually exclusive permutations to MIMO transmitters with N transmit antennas, allowing for reduced computational complexity in channel estimation by employing a training sequence and nulls across antennas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of transmit antennas is increased to enhance MIMO system capacity, then the system capacity and reliability are improved, but the computational complexity of channel estimation increases

Engineering Contradiction:

Improvesystem capacityVSAvoidcomputational complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The training sequence is divided into multiple segments, each assigned to different transmit antennas in a time-switched manner. This segmentation allows the receiver to estimate channel coefficients for each antenna separately across different time intervals, reducing the overall computational complexity compared to simultaneous multi-antenna transmission

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs periodic time-switched transmission where different permutations of training sequences are transmitted at different time intervals. This periodic action enables the receiver to accumulate channel estimates over multiple periods, improving estimation accuracy while maintaining manageable computational complexity through time-division multiplexing

Inventive Principle:

Principle #19Periodic action

2Reliability

If more transmit antennas are employed to improve reliability, then the reliability is enhanced, but the computational complexity for channel estimation increases

Engineering Contradiction:

ImprovereliabilityVSAvoidcomputational complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The training sequence is divided into multiple segments, each assigned to different transmit antennas in a time-switched manner. This segmentation allows the receiver to estimate channel coefficients for each antenna separately across different time intervals, reducing the overall computational complexity compared to simultaneous multi-antenna transmission

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs periodic time-switched transmission where different permutations of training sequences are transmitted at different time intervals. This periodic action enables the receiver to accumulate channel estimates over multiple periods, improving estimation accuracy while maintaining manageable computational complexity through time-division multiplexing

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS7382832B2Scalable time-switched preamble supplement generator, method of generating and multiple-input, multiple-output communication system employing the generator and method

Publication Date: 2008.06.03 TEXAS INSTRUMENTS INC

AI summary

The present invention provides a time-switched preamble supplement generator for use with a multiple-input, multiple-output (MIMO) transmitter employing N transmit antennas wherein N is at least two. In one embodiment, the time-switched preamble supplement generator includes an initial preamble supplement formatter configured to provide a first permutation of a set of preamble supplements to the N transmit antennas during an initial time interval. The first permutation includes a single first preamble supplement and at least one second preamble supplement. The time-switched preamble supplement generator also includes a subsequent preamble supplement formatter coupled to the initial preamble supplement formatter and configured to provide (N−1) mutually exclusive further permutations of the set to the N transmit antennas during (N−1) subsequent time intervals.