On the throughput of in-band full-duplex communication in wireless systems

Official URL: http://risc01.sabanciuniv.edu/record=b1620413 (Table of Contents)

Proliferation of mobile devices and explosion in data intensive applications have led to serious spectrum crunch and stimulated the pursuit of new wireless communication techniques to utilize the scarce wireless spectrum assets more e ciently. As one of the promising technologies considered for next generation wireless communications, in-band full-duplex has been shown to have a great potential to alleviate this problem due to doubled spectral e ciency. Unlike half-duplex radios, which need to transmit and receive at di erent times, or out-of-band full-duplex radios, which devote di erent frequency bands to transmission and reception, in-band full-duplex radios are capable of simultaneously transmitting, while receiving over the same frequency band at the cost of self-interference that results. In this thesis, via extensively conducted experiments, we compare the performance of in-band full-duplex with that of half-duplex in fundamental communication scenarios such as two way communication, one way two hop communication and two way two hop communication, clearly identifying the conditions under which inband full-duplex outperforms half-duplex. Next, we extend our study to evaluate in-band full-duplex in multihop wireless networks, considering a linear topology. We obtain closed form analytical expressions for optimum transmission power policy in the two hop case and a linear programming and binary search based solution for the multihop case to compute the optimal transmission power levels. Our in-band full-duplex solution which takes into account full-interference is shown to outperform half-duplex transmission by a factor of 2.77 at low transmission power level, and by a factor of 1.81 at high transmission power level. We also incorporate our power solution with routing algorithms for adhoc networks. We compare the end-to-end throughput performance of the proposed joint routing & power allocation solution to that of half-duplex, direct transmission and an existing one-hop interference based in-band full-duplex transmission strategy. Our numerical experiments considering practical, low power systems such as femto cells and Zigbee show that proposed joint routing & power control mechanism provides 30% throughput improvement, relative to the existing in-band full-duplex solution with one hop interference, while it o ers ve times throughput, relative to halfduplex transmission even for moderate (80dB) SI cancellation levels.