LTE Amplifier Performance Optimization

A major challenge facing designers of subsystems and systems for LTE (Long Term Evolution) networks is assuring backwards compatibility with existing GSM (Global System for Mobile Communications) and UMTS (Universal Mobile Telecommunications System) technology. To accomplish this, LTE designs must incorporate MIMO (multiple input, multiple output) technology, complex modulation schemes, and other advanced features.

As a result, designers must wrestle with resulting engineering challenges, including extremely strict requirements for ACLR (adjacent channel leakage ratio) and EVM (error vector magnitude). Designers typically use filters to reduce ACLR, but this necessitates tradeoffs in order to maintain EVM performance. For example, by incorporating a filter to reduce out-of-band distortion and ACLR, you can introduce in-band distortion and increase EVM (or vice versa).

AWR has created a test bench within its Visual System Simulator (VSS) software can help designers manage the trade-off process for an LTE power amplifier (PA). VSS incorporates all requirements for the 3rd Generation Partnership Project’s (3GPP) specifications for the physical layer, as outlined in the 3GPP LTE standard.

Download this application note to see how VSS can be used to optimize the performance of your LTE PA, ensure EVM and ACLR meet 3GPP requirements for compatibility, and simplify your overall process/work flow.