Expanded Constellation Mapping for Enhanced Far-End-Cross-Talk Cancellation in G.fast

We propose the novel concept of expanded constellation mapping (ECM) for maximising the received signal power, while cancelling the far-end-cross-talk in copper-based wireline communications. The goal of ECM is to beneficially map the transmitted symbol vector to its expanded constellation set by carefully exploiting the copper channels' specific characteristics. To elaborate, ECM is comprised of the control entity and of the match entity, where the former determines how the ECM would be applied, while the latter searches for the best mapping of the transmitted symbol vector to the expanded constellation set. Our numerical results demonstrate that with the aid of the ECM, more than 25-dB power efficiency gain may be achieved over linear vectoring. Similarly, about 20-dB gain may be achieved over non-linear vectoring. From an implementation point of view, the ECM imposes minimal structural changes on G.fast, whilst exhibiting beneficial reconfigurability and compatibility.