Performance Evaluation of IDMA Scheme in Wireless Communication

Table of Contents

1. Introduction

1.1. Development of Wireless Communication Systems

1.2. Multiple Access Schemes

1.2.1. FDMA Scheme

1.2.2. TDMA Scheme

1.2.3. CDMA Scheme

1.3. Motivation

1.4. Problem Statement

1.5. Research Contributions

1.6. Thesis Organization

2. Overview of Interleave-Division Multiple-Access (IDMA) Scheme

2.1. Introduction

2.2. Interleavers in Digital Communication

2.3. Interleavers in IDMA Scheme

2.4. Mechanism of Interleaving Process

2.5. Interleave-Division Multiple-Access (IDMA) Scheme

2.5.1. Comparison of CDMA and IDMA Schemes

2.5.2. IDMA Transmitter and Receiver

2.5.2.1. Basic Primary Signal Estimator (PSE) Function

2.5.2.2. Algorithm for Chip-By-Chip Detection

2.5.2.3. Decoder (DEC) Function

2.5.3. IDMA over Multipath Channels

2.6. Literature Review

2.7. Simulation of IDMA Scheme

2.8. Conclusions

3. Performance Evaluation of Tree Based Interleaver (TBI) in IDMA Scheme

3.1. Introduction

3.2. Motivation

3.3. Mechanism of Tree Based Interleaver (TBI)

3.4. Performance Evaluation of Tree Based Interleaver

3.5. TBI with Unequal Power Allocation Algorithm

3.5.1. Unequal Power Allocation Mechanism

3.5.2. Numerical Results

3.6. Conclusions

4. Performance Evaluation of Tree Based Interleaver in IDMA Scheme with Maximal Ratio Combining (MRC) Diversity

4.1. Introduction

4.2. Diversity Mechanisms

4.2.1. Frequency Diversity

4.2.2. Time Diversity

4.2.3. Space Diversity

4.2.3.1. Transmit Diversity

4.2.3.2. Receive Diversity

4.3. Combining Mechanisms

4.3.1. Selection Combining

4.3.2. Maximal Ratio Combining (MRC)

4.3.3. Equal Gain Combining (EGC)

4.4. Performance Evaluation of IDMA Scheme with MRC Diversity

4.4.1. IDMA Scheme with Maximal Ratio Receiver Combining (MRRC) Diversity

4.4.2. IDMA Scheme with Maximal Ratio Transmitter Combining (MRTC) Diversity

4.5. Simulation Results

4.5.1. Simulation Results of IDMA Scheme using MRRC Diversity

4.5.2. Simulation Results of IDMA Scheme using MRTC Diversity

4.6. Conclusions

5. Correlation Analysis and FPGA Implementation of Interleavers

5.1. Introduction

5.2. Motivation

5.3. Design Criteria for Interleavers in IDMA Scheme

5.4. Correlation in Interleavers

5.5. Correlation Analysis of Interleavers

5.6. Interleaving Mechanism in IDMA Scheme

5.6.1. Random Interleaving (RI) Mechanism

5.6.2. Master Random Interleaving (MRI) Mechanism

5.6.3. Tree Based Interleaving (TBI) Mechanism

5.7. Performance Comparison of Interleavers on FPGA Implementation

5.7.1. Summary of Hardware

5.7.2. Final Register Report

5.7.3. Device Utilization Report

5.7.4. Timing Summary Report

5.8. Conclusions

6. Conclusions

6.1. Suggestions for Further Investigations

Objectives and Research Focus

The primary objective of this thesis is to propose and evaluate an efficient interleaving mechanism, termed Tree Based Interleaving (TBI), for Interleave-Division Multiple-Access (IDMA) systems. The research addresses the challenges of computational complexity, memory requirements, and bandwidth consumption that are associated with existing random and master random interleaver generation methods, while maintaining robust performance in terms of Bit Error Rate (BER) and hardware implementation efficiency.

• Analysis of Interleave-Division Multiple-Access (IDMA) systems and interleaving techniques.
• Development of the Tree Based Interleaving (TBI) mechanism to optimize computational load and memory usage.
• Performance evaluation of TBI in uncoded, coded, and diverse communication environments.
• Correlation analysis of various interleaver mechanisms to understand their behavior with increasing user counts.
• Hardware implementation and validation of TBI on FPGA systems to compare timing and resource utilization.

Excerpt from the Book

Summary of Chapters

1. Introduction: Provides an overview of the evolution of wireless communication systems and introduces IDMA as a promising alternative for future mobile communication.

2. Overview of Interleave-Division Multiple-Access (IDMA) Scheme: Explains the technical foundations of interleaving and the specific architecture of IDMA systems, including transmitter and receiver components.

3. Performance Evaluation of Tree Based Interleaver (TBI) in IDMA Scheme: Presents the proposed TBI mechanism, evaluates its performance, and demonstrates its superiority in computational complexity and memory efficiency.

4. Performance Evaluation of Tree Based Interleaver in IDMA Scheme with Maximal Ratio Combining (MRC) Diversity: Investigates the effectiveness of TBI within systems employing various diversity mechanisms to mitigate fading and improve reliability.

5. Correlation Analysis and FPGA Implementation of Interleavers: Details the cross-correlation properties of different interleaver types and validates their hardware feasibility through FPGA implementation.

6. Conclusions: Summarizes the thesis findings and suggests potential future research directions for enhancing IDMA-based communication.

Keywords

Wireless Communication, IDMA, Interleaver, Tree Based Interleaver, Bit Error Rate, Computational Complexity, FPGA, Maximal Ratio Combining, Diversity, Multiple Access Interference, Orthogonality, Memory Optimization, Signal Processing, Telecommunications, BER Performance

Frequently Asked Questions

What is the fundamental focus of this research?

This research focuses on the performance evaluation and optimization of interleaving mechanisms in Interleave-Division Multiple-Access (IDMA) wireless communication systems.

What are the primary challenges addressed by this thesis?

The thesis addresses issues regarding computational complexity, excessive memory requirements for storing interleaver patterns, and bandwidth consumption in IDMA systems.

What is the main goal of the proposed Tree Based Interleaving (TBI) mechanism?

The goal is to provide a user-specific interleaver generation method that is easy to implement, consumes minimal memory, and maintains excellent performance compared to existing random and master random interleaver approaches.

Which methodology is used to validate the proposed interleaver?

The validation is carried out through analytical modeling, extensive MATLAB-based simulations for BER performance, and hardware validation via FPGA (Field-Programmable Gate-Array) implementation on a Xilinx platform.

What is the role of the interleaver in an IDMA system?

In IDMA systems, interleavers serve as the core component for user separation, replacing the traditional spreading sequences used in CDMA to ensure users do not collide.

How does the performance of TBI compare to existing methods?

The TBI mechanism shows significantly lower computational complexity compared to master random interleavers and requires far less memory than purely random interleaver approaches, while delivering similar BER results.

How is MRC diversity applied in this research?

Maximal Ratio Combining (MRC) is incorporated as a diversity technique at the receiver and transmitter to combat multipath fading, further demonstrating the robustness of TBI in real-world propagation conditions.

What are the key conclusions regarding hardware implementation?

The FPGA implementation confirms that TBI requires the least number of hardware components (D-flip-flops, logic slices) and offers the best timing performance among the compared interleaving schemes.