In the first three posts of this seven part series, Ahmed discusses both theoretical and practical issues when implementing MIMO technologies, such as those used in the upcoming LTE releases. He examines a sample performance analysis and looks at the implications of the results. In the subsequent posts, Ahmed turns towards the future and looks at the research and design of next-generation networks.
Here’s links to the three posts in this series:
- Massive MIMO – Part 1: Introduction: From theory to implementation
- Massive MIMO – Part 2: A few lessons learned from asymptotic information theoretic analysis
- Massive MIMO – Part 3: Capacity, coherence time and hardware capability
- Massive MIMO – Part 4: Massive MIMO and small cells, the next generation network
- Massive MIMO – Part 5: The need for practical prototyping and implementation
- Massive MIMO – Part 6: Estimation and capacity limits due to transceiver impairments
- Massive MIMO – Part 7: Research issues
A recap of Part 1
Part 1 looks the current state of MIMO technology and how massive MIMO can offer tremendous gains, albeit at the expense of increasing complexity and implementation challenges.
A recap of Part 2
Part 2 addressed key lessons learned from asymptotic information theoretic analysis on the asymptotic throughput using matching filter for detection and/or eigen-beamforming precoder for transmission.
A recap of Part 3
Part 3 looks at the use of TDD as a duplexing mode being a key enabler for a heterogeneous network architecture with the potential to provide ubiquitous coverage and unprecedented spectral area efficiencies. The post concludes with two key implications:
- The importance of the processing hardware in regards to coherence time for a given maximum number of antennas and served user terminals.
- More research being required on adaptive precoder design to maximize the achieved capacity .
A recap of Part 4
Part 4 discusses the future of massive MIMO beyond the conventional LTE 4G evolution path. Increasing network capacity by a factor of thousand over the next ten years can be achieved by massive network densification through the use of small cells.
A recap of Part 5
Part 5 discusses massive MIMO from an implementation and prototyping perspective. While the research is promising, without experimental validation, it is difficult, if not impossible, to predict the practicality and performance of these proposed techniques on real hardware in complex, rapidly varying, real-world conditions. Suitable experimental platforms, like Nutaq’s Kermode XV6 AdvancedTCA computer blade, are required.
A recap of Part 6
Part 6 looks at the effects transceiver hardware impairments have on massive MIMO systems, namely how transceiver quality limits the downlink and uplink capacities as the antenna array increases in size.
A recap of Part 7
Part 7 concludes the series by looking at the future of massive MIMO and the challenges it faces.