Wireless networks, for example Long Term Evolution (LTE) and LTE-Advanced (LTE-A) networks, may be heterogeneous networks that include “macro cells,” providing higher power/wider area coverage, and “small cells,” providing lower power/reduced area coverage. Small cells may include “femto cells,” suitable for home or office coverage and “pico cells,” for larger indoor environments such as shopping centers. A serving cell for a wireless mobile device, for example User Equipment (UE), may be a base station that includes an evolved Node B (eNB) transceiver to provide network access to the UE within the associated cell coverage area.
As network traffic increases, new system enhancements are being implemented to improve bandwidth utilization and efficiency including the introduction of new carrier types (NCTs), or carriers with reduced overhead, or other backwards compatible carriers, with modified frame structures and synchronization methods. A heterogeneous network may include a mixture of eNBs operating with an NCT and a legacy or Backward-compatible Carrier Type (BCT). Some efforts to increase downlink (DL) throughput may include the reduction or removal of legacy physical control channels or cell specific reference signals (CRS). For example the density of the CRS may be reduced in the frequency domain, the time domain or both, requiring alternative methods for the UE to synchronize with the eNB.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art.
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USPTO Backgrounds