CDMA NOC Architecture

          Network on chip or network on a chip (NoC or NOC) is a communication subsystem on an integrated circuit (commonly called a "chip"), typically between intellectual property (IP) cores in a system on a chip (SoC). NoCs can span synchronous and asynchronous clock domains or use unclocked asynchronous logic. NoC technology applies networking theory and methods to on-chip communication and brings notable improvements over conventional bus and crossbar interconnections. NoC improves the scalability of SoCs, and the power efficiency of complex SoCs compared to other designs. Several researchers are investigating the possibility of designing NoCs with wireless interconnects. Recently, the design of a wireless NoC based on CMOS Ultra Wideband (UWB) technology was proposed Zhao et al. [1]. In Zhao et al. [1] a wireless Media Access Control (MAC) protocol based on time-multiplexing of ultra-short pulses from the UWB transceivers was proposed to enable concurrent use of the wireless channels. A wireless NoC with unequal RF transceivers is proposed in Zhao et al. [2] to improve the performance in a conventional mesh topology overlaid with wireless interconnects. In Lee et al. [3] the design of on-chip wireless communication network with miniature antennas and simple transceivers that operate at the sub-THz range of 100–500 GHz has been proposed. Design of a wireless NoC using the small-world topology using carbon nanotube (CNT) antennas operating in the THz frequency range is also presented by various researchers. Due to the possibility of tuning CNT antennas to various frequencies it was possible to communicate using Frequency Division Multiplexing (FDM) on non-overlapping channels. However, challenges of fabrication and integration of CNT antennas with CMOS processes may hinder its adoption in the near future. In Deb et al. [4] design of a wireless NoC with CMOS compatible mm-wave transceivers was proposed. The access to transfer data over the wireless channel was shared between multiple transmitters using a token passing mechanism. This granted access of the wireless medium to only one transmitter at a time. In Wang et al. [5] digital implementations of a CDMA-based wireline NoC were proposed.

However, both these CDMA based NoCs have centralized controllers that allocate codes to the transceivers and add the encoded CDMA bits (chips) prior to sending over the NoC fabric. Such centralized control schemes are not suitable for the distributed MAC protocol desired in the Wireless NoC.


[1] D. Zhao, Y. Wang, J. Li, and T. Kikkawa. Design of multi-channel wireless NoC to improve on-chip communication capacity. In Proceedings of the IEEE/ACM International Symposium on Networks-on-Chip. 177–184, 2011

[2] D. Zhao and R. Wu., Overlaid mesh topology design and deadlock free routing in wireless network-on chip. In Proceedings of the IEEE/ACM International Symposium on Networks-on-Chip, 2012

[3] S.-B. Lee, S.-W. Tam, I. Pefkianakis, S. Lu,M. F. Chang, C. Guo, G. Reinman, C. Peng, M. Naik, L. Zhang, and J. Cong. 2009. A scalable micro wireless interconnect structure for CMPs. In Proceedings of the ACM Annual International Conference on Mobile Computing and Networking (MobiCom’09). 20–25.

[4] S. Deb, A. Ganguly, K. Chang, P. P. Pande, B. Beizer, and D. Heo. 2010. Enhancing Performance of Network-on-Chip Architectures with Millimeter-Wave Wireless Interconnects. In Proceedings of the IEEE International Conference on Application-specific Systems Architectures and Processors. 73–80.

[5] X. Wang, A. Tapani, and J. Nurmi. 2007. Applying CDMA technique to network-on-chip. IEEE Trans. VLSI 15, 10, 1091–1100.

[6] Maurizio Palesi, Masoud Daneshtalab, “Routing Algorithms in Networks-on-Chip”, Springer Science & Business Media, 2013