In Part I  of this two-part paper, we provide uncoded bit error probability (BEP) analysis of various transmittedreference (TR) schemes by developing an analytical framework based on the sampling expansion approach. In this paper, the effect of narrowband interference (NBI) is taken into account to derive uncoded BEP expressions of TR and differential TR (DTR) signaling with an autocorrelation receiver (AcR). For simplicity, our NBI is modeled as a single tone interferer with Rayleigh distributed amplitude and an uniformly distributed random phase. We quantify the effect of NBI and channel power dispersion profile (PDP) on the optimum integration interval of AcR. Unlike the NBI-free situation, the optimum integration interval of AcR is not necessarily close to the delay spread, and depends on the signal-to-interference ratio (SIR), the signal-to-noise ratio (SNR) and the channel PDP. Furthermore, our results also allow us to compare the NBI sensitivity of TR and DTR signaling.