In modern era of wireless communications Viterbi decoder (VD) is widely used to decode Binary Convolution Codes (BCC) in many Wi-Fi systems such as WLAN 802.11a/n/ac/ah, Satellite communications, Mobile communications etc. To obtain high decoding performance, the constraint length of BCCs is basically quite long. Whereas the complexity of VD is exponentially affected by BCCs constraint length. Therefore Viterbi decoding of BCCs with long constraint length cannot be used for systems or devices like Internet of Things (IoT) sensors, that require low power and less hardware cost. In this work a less-complex Kmin Viterbi Decoder (KVD) is proposed in which the decoder`s complexity is inconsiderably affected by constraint length. For the decoding performance evaluation such as Packet Error Rate (PER) and Bit Error Rate (BER) of the proposed decoder, a BCC with constraint length k = 7 is used. This code is required in Wi-Fi systems such as IEEE 802.11a/n/ac/ah. A new standard 802.11ah for IoT applications is considered for simulation. The PER performance of proposed KVD decoder in relation with several factors such as channel type, modulation type, decoder`s trace-back length and packet size has been evaluated. The proposed KVD achieves the same PER performance as the orthodox VD does, while its complexity is reduced by approximately 12.80 times to 21.33 times shown in result analysis.

kmin Viterbi Decoder (KVD); Binary Convolution Code (BCC); IoT sensors; Packet Error Rate (PER); Bit Error Rate (BER); Wireless Transceiver; 802.11 a/n/ac/ah WLAN

[1] Liu T.Y., Zhou G.: “Key Technologies and Applications of Internet of Things”. In the Proceedings of fifth Int. Conf. on Intelligent Computation Technology and Automation (ICICTA-2012) , Xian, pp.197–200, 2012.

[2] Girau R, Martis S, Atzori L, “Lysis: a platform for IoT distributed applications over socially connected objects”, IEEE Internet of Things Journal (IoTJ), Vol.4(1), pp. 1-12, 2016.

[3] Tran T. H., Nagao Y., Kurosaki M., Sai, B., Ochi, H.: “ASIC Implement of 600Mbps IEEE 802.11n 4x4 MIMO Wireless LAN System”. In the Proceedings of 14th IEEE Int. Conf. on Advan. Commu. Tech. (ICACT-2012), Korea, pp. 360–363, 2012.

[4] Viterbi, A.: “Error bounds for convolutional codes and an asymptotically optimum decoding algorithm. IEEE Transactions on Information Theory” Vol.1(1) pp. 260-269, 1967.

[5] Dutta R., Van Der Mast C., “Virtex 4 FPGA Implementation of Viterbi Decoded 64-bit RISC for High Speed Application using Xilinx”, International Journal of Computer Applications (IJCA), Vol.88(14), pp. 30-35, 2014.

[6] Maharatna K., Troya A., Krstic M., Grass E.: “On the implementation of a low-power IEEE 802.11a compliant Viterbi decoder”. In the Proceedings of 19th Int. Conference on VLSI Design (DOI:10.1109/VLSID). Bombay, pp.124, 2006.

[7] Chakraborty D, Raha P, Bhattacharya A, Dutta R; “Speed Optimization of a FPGA based modified Viterbi Decoder”, in the Proc. of IEEE Int. Conf. on Computer, Communication and Informatics (ICCCI-2013), Coimbatore, pp. 321-326; 04-06 January, 2013. ISBN: 978-1-4673-2907-1.
[8] Sandesh, Y.M., Kasetty, R.: “Implementation of Convolution Encoder and Viterbi Decoder for Constraint Length 7 and Bit Rate ½”, Int. Journal of Engineering Research and Applications Vol.3(4), pp. 42-46, 2013.

[9] IEEE 802.11 committee: Part 11: “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications”. IEEE Std. 802.11a, Vol.38(6), 1999.

[10] Tran T.H., Nagao Y., Ochi H.: “Algorithm and Hardware Design of A 2D Sorter-based K-best MIMO Decoder”. EURASIP Journal on Wireless Communications and Networking DOI: 10.1186/1687-1499-2014-93, Vol.8(3), 2014.

[11] Dutta R, Pradhan PC, Sharma P, Guha S: “VoIP Technology based modified CAC scheme for IEEE 802.11 Wireless LANs”, In the Proceedings of Int. Conf. on Computation and Communication Advancement (IC3A) – 2013, West Bengal, pp. 174-180, 2013.

[12] Dutta R, Chaudhuri D, Mohanto B, Das M; “A Proposed DLCCS Algorithm for High Speed Operation & Implementation on FPGA”, International Journal Nanotechnology & Applications (IJNA), Vol.8(1), pp. 01-12, 2014.

[13] Liu Y.S., Tsai Y.Y.: “Minimum decoding trellis length and truncation depth of wrap-around Viterbi algorithm for TBCC in mobile WiMAX”, EURASIP Journal on Wireless Communications and Networking, Vol. 44(8) DOI: 10.1186/1687-1499-2011-111, 2011.