Low latency relaying schemes for next-generation cellular networks

The reduction in both user and control plane latency is a major goal for next generation (4G) cellular networks, specifically the Long Term Evolution-Advanced (LTE-A) standard. At the same time, relay stations, which introduce additional latency into transmissions, are seen as a potential means to improve cell spectral efficiency and coverage. This paper extends a number of existing relaying schemes to the case where a stricter latency constraint is applied. These low latency schemes are first evaluated for convolutional codes, for which they quickly approach the performance of full decoding at the relay with little additional latency over memoryless relaying. The schemes are then adapted for the turbo code in the LTE standard and shown to be preferable to full decoding and memoryless relaying for certain LTE-A relay types.