DSP-Assisted Channel Aggregation Options for Next-Generation Mobile Fronthauling

In this paper, we perform a performance comparison of two different solutions for next generation mobile fronthauling, both based on digital signal processing (DSP) channel aggregation options, but in the two variants usually indicated as Time Division Multiplexing Access (TDMA) and Frequency Division Multiplexing Access (FDMA). The two DSP-based options are here compared for the scenarios of 48 (20 MHz) LTE-A, 96 (20 MHz) LTE-A or 24 new radio NR (100 MHz) channels by means of simulation on realistic Intensity Modulation and Direct Detection optical fronthauling link. We report on spectral occupation, DSP complexity and error vector magnitude (EVM) as performance metrics. We show that TDMA option has more compact bandwidth, it does not require pre-emphasis to equalize per channel EVM and gives out a slightly better EVM performance than FDMA when the optical channel shows significant frequency roll-off towards higher channels.