Coherent cooperative relaying in low mobility wireless multiuser networks / Stefan Berger.

Format:

Book

Author/Creator:

Berger, Stefan, author.

Series:

Series in wireless communications ; Band 10

Language:

English

German

Subjects (All):

Wireless communication systems.

Physical Description:

1 online resource (348 pages).

Edition:

1st ed.

Place of Publication:

Berlin : Logos Verlag Berlin, [2010]

Summary:

Long description: In this thesis, several important aspects of cooperative wireless multiuser networks are investigated. The focus lies on coherent two-hop relaying networks where several amplify-and-forward (AF) relays assist the communication between multiple source-destination pairs. First, the impact of local oscillator (LO) imperfections and I/Q imbalance at the relays on two-hop relaying is investigated. A special focus lies on the comparison between frequency division duplexing (FDD) and time division duplexing (TDD) relays. Based on the observation that the direction in which a channel between two wireless nodes is measured has an impact on the estimate, phase synchronization requirements for coherent relaying networks are then found. Several channel estimation protocols that differ in the direction in which the single-hop channels are measured are furthermore identified and their performance is compared. Next, a very simple phase synchronization scheme is presented that provides a set of relays with a common LO phase. Two coherent beamforming schemes, namely multiuser zero-forcing (MUZF) and multiuser minimum mean squared error (MMSE) relaying, are then investigated. Finally, a real-world demonstrator for distributed wireless communication networks (called RACooN Lab) is presented. It was used to implement coherent cooperative communication schemes on a practical two-hop relaying network.

Contents:

Intro

1 Introduction

1.1 Relaying Schemes

1.2 Capacity Scaling

1.3 Diversity-Multiplexing Tradeoff

1.4 Hardware Imperfections

1.5 Real-World Demonstrators

1.6 Contribution and Outline

2 System Model

2.1 System Topology

2.2 Channel Model

2.3 Local Oscillator Phases and Equivalent Channels

2.4 Traffic Patterns and Input/Output Relation

2.5 Reference Scenario and Definition of the SNR

2.6 Average Sum Rate

3 Implementation Issues

3.1 Relay Block Diagram

3.2 LO Imperfections

3.2.1 LO Frequency Offset

3.2.2 Phase Noise

3.2.3 Impact on AF Relaying

3.3 I/Q Imbalance

3.3.1 Transmitter Imbalance

3.3.2 Receiver Imbalance

3.3.3 Equivalent Baseband System Model

3.3.4 Impact on Signal Quality

4 Channel Estimation

4.1 Channel Estimation and Dissemination

4.2 Coherent Distributed Beamforming

4.3 Channel Update Rate

4.4 Channel Estimation Protocols

4.4.1 Performance Measure

4.4.2 Compound Channel Estimates and Required Number of Channel Uses

4.4.3 Impact of Noise

4.4.4 Performance Comparison

5 Distributed Phase Synchronization

5.1 Relay Phase Noise

5.1.1 Phase Beacon at the Relays

5.1.2 Phase Error

5.2 Distributed Phase Synchronization Schemes

5.2.1 Slave-Based Scheme

5.2.2 Master-Based Scheme

5.2.3 Comparison

5.2.4 Phase Error

6 Gain Allocation Schemes

6.1 Transmit Power Constraint

6.2 Multiuser Zero-Forcing Relaying

6.2.1 Traffic Pattern III

6.2.2 Traffic Pattern IV

6.2.3 Impact of Phase Estimation Error

6.2.4 Simulation Results

6.3 Multiuser MMSE Relaying

6.3.1 Linear Relaying, Generic Case

6.3.2 Linear Relaying, Special Case

6.3.3 Linear Distributed Antenna System, Generic Case

6.3.4 Linear Distributed Antenna System, Special Case

6.3.5 Impact of Phase Noise

6.3.6 Simulation Results.

6.4 Impact of Relay Imperfections

6.4.1 Noisy CSI

6.4.2 Phase Noise

6.4.3 Phase Synchronization Error

7 The RACooN Lab

7.1 General Description

7.1.1 Baseband Processing

7.1.2 System Operation

7.1.3 Real-Time Features

7.2 System Characteristics

7.2.1 Transmit Power

7.2.2 Analog Gain Control

7.2.3 Imperfections

7.3 Channel Measurements

7.3.1 Measurement Scenario

7.3.2 RACooN Setup

7.3.3 Measurement Results

7.4 RACooN Demonstrator

7.4.1 System Setup

7.4.2 Transmission Cycle

7.4.3 Results

8 Conclusions and Outlook.

Notes:

Description based on print version record.

PublicationDate: 20100815

ISBN:

3-8325-9923-1