A Communication Theoretical Modeling of Single-Walled Carbon Nanotube Optical Nanoreceivers and Broadcast Power Allocation

Carbon nanotube (CNT) with its ground-breaking properties is a promising candidate for future nanoscale communication networks. CNTs can be used as on-chip optical antenna for wireless interconnects. Carbon nanotube field-effect transistors (CNTFETs) show significant performance as photodetectors due to wide spectral region and tunable bandgap. In this paper, CNTFETs composed of semiconducting single-walled carbon nanotube (SWNT) and metal contacts (M-SWNT-M) are used as photodiode receivers in nanoscale optical communication by theoretically modeling diameter-dependent characteristics for shot-, dark-, and thermal-noise-limited cases. Bit error rate (BER), cutoff bit rate, and signal-to-noise ratio performance are analyzed for intensity modulation and direct detection modulation. The multireceiver CNT nanoscale network topology is presented for information broadcast and the minimum SNR is maximized solving NP-hard max-min power allocation problem with semidefinite programming relaxation and branch and bound framework. The significant performance improvement is observed compared with uniform power allocation. Derived model is compared with existing experiments and hundreds of Mb/s data rate is achievable with very low BERs. Furthermore, optimization gain is highest for thermal-noise-limited case while the shot-noise-limited case gives the highest data rate.