The document discusses various approaches for mitigating interference in femtocell networks, including power control, cognitive approaches, fractional frequency reuse and resource partitioning, femto-aware spectrum arrangement, clustering femtocells, beam subset selection strategy, and collaborative frequency scheduling. It provides brief descriptions and comparisons of the advantages and disadvantages of each approach.

1. Mohamad Taghi Shaykhan
Graduate Student of Information Technology Engineering
Amirkabir University of Technology
Femtocells:
Interference Mitigation
Page 1 of 30Femtocell Introduction Challenges Interference Mitigation

2. Interference Mitigation Approaches
POWER CONTROL APPROACH
COGNITIVE APPROACH
FRACTIONAL FREQUENCY REUSE (FFR) AND RESOURCE
PARTITIONING
FEMTO-AWARE SPECTRUM ARRANGEMENT SCHEME
CLUSTERING OF FEMTOCELLS
BEAM SUBSET SELECTION STRATEGY
COLLABORATIVE FREQUENCY SCHEDULING

3. POWER CONTROL APPROACH
 Cross-tier interference
mitigation (in overlaid
network)
 Proactive (open loop power
setting) and Reactive (closed
loop power setting)

4. POWER CONTROL APPROACH
Advantages & Disadvantages
 Cooperation is not required
(among Femto & Macro)
 Efficiency
 Cooperation is required (among
Femto & Femto)
 Transmission mode: Downlink
 Complexity

5. COGNITIVE APPROACH
 Co-tier interference
mitigation (in overlaid and
underlaid network)
 Distributed spectrum sensing

6. COGNITIVE APPROACH
 Cooperation is not required
(among Femto & Macro)
 Efficiency
 Cooperation is required (among
Femto & Femto)
 Transmission mode: Downlink
 Complexity
Advantages & Disadvantages

7. FRACTIONAL FREQUENCY REUSE (FFR) AND
RESOURCE PARTITIONING
Co-tier Interference Cross-tier Interference

8. FRACTIONAL FREQUENCY REUSE (FFR) AND
RESOURCE PARTITIONING
 Co-tier and Cross-tier Interference
 Transmission mode: Uplink and
Downlink
 Cooperation is not required
(among Femto & Macro)
 Complexity
 Efficiency
 Cooperation is required (among
Femto & Femto)
Advantages & Disadvantages