Seok-Ki Ahn

Adaptive Sliding-Window Coded Modulation in Cellular Networks

The sliding-window superposition coding scheme aims to mitigate intercell interference at the physical layer by achieving the simultaneous decoding performance with point-to-point channel codes, low- complexity decoding, and minimal coordination overhead. The associated sliding-window coded modulation (SWCM) scheme can be readily implemented using standard off-the-shelf codes, such as the standard LTE turbo code, and tracks the information-theoretical performance guarantee of sliding-window superposition coding. This paper investigates how the basic SWCM scheme performs for the Ped-B fading interference channel model and proposes several improvements in transceiver design, such as soft decoding, input bit-mapping and layer optimization, and power control. Our enhanced SWCM scheme achieves the rates higher than those of the basic SWCM scheme by 10% to 20%, which already shows a significant gain over existing schemes that ignore modulation or coding information of interfering signals. This result confirms the potential of SWCM as a basic building block for physical-layer interference management in 5G and subsequent generations of cellular networks.

Interference Management via Sliding-Window Coded Modulation for 5G Cellular Networks

SWCM aims to mitigate the adverse effects of interference at the physical layer by tracking the optimal maximum likelihood decoding performance with low-complexity decoding and minimal coordination overhead. This article reviews the basic structure of the SWCM scheme built on the principles of network information theory, and discusses how it can be extended and implemented in practical wireless communication systems. Using a representative implementation based on LTE OFDM MIMO systems, extensive link-level and system-level performance simulations are carried out, which demonstrate that SWCM offers significant gains for all users over conventional interference-aware communication schemes. Network operating prerequisites for SWCM are also discussed to facilitate the standardization effort for its adoption in the fifth generation cellular network.