Achieving High Bandwidth Efficiency under Partial-Band Noise Jamming

This paper examines how to achieve high bandwidth efficiency while remaining robust to partial-band noise jamming (PBNJ). The main conclusion is that using higher order modulation with moderate code rates (HMMC) results in less PBNJ loss compared to using lower order modulation and high code rates close to unity (LMHC). For example, to achieve a bandwidth efficiency of R = 1.8 bits/sym, the modulation and code rate combination (ModCod) of 8PSK 3/5 has less PBNJ loss than QPSK 9/10. Similarly, to achieve R = 2.66 bits/sym, 16APSK 2/3 has less PBNJ loss than 8PSK 8/9. In the examples shown in this paper, the HMMC options suffer less than 0.5 dB PBNJ loss, while the LMHC options suffer PBNJ loss up to 5 dB. This paper also presents a theoretical analysis tool for estimating the amount of PBNJ loss, which is then validated via simulation. The analytical approach takes much less computation time and predicts about 80% of the PBNJ loss, averaged over the four cases studied. The theoretical model starts with the Shannon limit for Additive White Gaussian Noise (AWGN) channel for both infinite and finite constellations and then extends to include 1) PBNJ effects on average channel capacity, 2) the effect of interleaving over finite number of hops using a method based on binomial distribution, and 3) the effects of various parameters on PBNJ loss, including number of interleaving hops, jammer power, and required code word error rate. The analysis assumes perfect SNR knowledge at the receiver. Simulations are performed using DVB-S2 forward error correction (FEC) codes.