Shu (Marloon) Wang

There are many parameters or specifications defined for quantifying the performance of a receiver design and implementation. Among them, the most notable includes the reference sensitivity power level (REFSENS) and the Total Isotropic Sensitivity (TIS), which are widely used for specify how sensitivity a receiver is. More sensitive a receiver is, less power it requires for maintaining a reliable communication and better performance it is believed to have. In general, REFSENS measures the performance of the receiver module with considering its down-converting performance, demodulation/decoding capability and self-generated interference/noise. Per 3GPP definition, REFSENS specifically denotes the minimum mean power applied to each applicable receive antenna port at which the throughput shall meet or exceed the requirements, which is not less than 95% of the maximum throughput of the specified reference measurement channel. See §7.3, Annexes A.2.2 (for FDD), A.2.3 (for TDD) and

Less than two years ago, I had a client who challenged me to improve the downlink sensitivity of a LTE receiver by 10 dB while maintaining its small form factor and battery life. At the beginning, I was so puzzled by her intention and tried hard to convince her that the mobile network in whole may not benefit much from such a single improvement. There are many other factors, e.g., battery life, downlink-uplink coupling, device cost, inter-cell interference and user capacity, to consider.  One year later, I was again amazed by the rapid rise of so many internet of things (IoT) systems each pretty much claiming a   ~170 dB link budget  and a  ~10 years battery life , in addition to its ultra-low device cost, enormous user capacity supporting tens-thousand devices per base station per channel user, and, did I mention this,  in a very noisy unlicensed ISM band.  goo.gl/pJb0KF .  Think about this, a household  Alkaline AA battery  can only supply up to 3900 mWh / 8760 h =  0.45 mW averaged