new carrier type (NCT) Improve system performance allowing Non backward compatible carrier . In LTE Release 12 or Release 11, the NCT is a non-backward compatible carrier for boosting throughput by reducing the emphasis on common reference symbols (CRS). The NCT can reduce and/or eliminate legacy control signaling and/or CRS. In addition, the density of the CRS may be reduced in both the frequency domain and the time domain. The new carrier type can enhance spectral efficiency, improved support for heterogeneous networks (HetNets), and improve energy efficiency. Either a synchronized or unsynchronized carrier type can support the new carrier type. The new carrier type can be non-stand alone or stand alone
Enodeb deploying an NCT carrier does not need to transmit any control signal CRS in most of the subframes when there is no traffic in the cell.
Legacy control channels, such as the physical broadcast channel (PBCH), the physical hybrid automatic repeat request (ARQ) indicator channel (PHICH), the physical control format indicator channel (PCFICH), and the physical downlink control channel (PDCCH) that rely on CRS for demodulation may be optimized for NCT.