A STUDY ON ENHANCING THE OFDM SCHEMES IN WIRELESS COMMUNICATION

This paper presents enhancing the OFDM schemes in wireless communication techniques for ultra-low power (ULP) devices. The concept of embedded back-channel communication is proposed to enable a variety of new applications by interconnecting heterogeneous ULP devices through existing Orthogonal Frequency Division Multiplexing (OFDM) based Wi-Fi (IEEE 02.11a/g/n/ac) networks. The proposed back-channel communication allows ULP devices to decode messages embedded in Wi-Fi OFDM packets even if these ULP devices are incapable of demodulating OFDM. The proposed back-channel signaling has unique properties that are easily detectable by non-Wi-Fi ULP receivers consuming sub-mW of active power. The proposed scheme eliminates the need for specialized transmitter hardware or dedicated channel resources for embedded back-channel signal transmission. Instead, carefully sequenced data bit streams will generate back-channel messages from already-deployed Wi-Fi infrastructure without any hardware Modification. This paper demonstrates that Wi-Fi OFDM back-channel communication is feasible in various modulation formats such as pulse position modulation (PPM), pulse phase shift keying (PPSK), or frequency shift keying (FSK). Systematic algorithms are unveiled to create back-channel messages in various modulation formats from a WiFi standard compliant Datapath. Comprehensive bit error rate (BER) performance analysis of various Wi-Fi back-channel communication schemes is derived and validated in realistic multi-path frequency selective fading channels. so the most important aspect of this proposed work is latency and energy consumption so ULP is efficiently implemented in order to provide the optimize and efficient OFDM schemes in wireless communication.