SNR estimation of SS communication using orthogonal code for fading channels

Spread spectrum communication has been used in many fields. In this paper, we propose novel SNR (signal to noise ratio) estimation of SS (spread specyrum) communication for fading channels. In DS(direct sequence)/SS communication, a signal is spread by using a spreading code. In the method, we use sequences (a sequence) that are (is) orthogonal to the spreading code. If we use plural sequences, these sequences must be orthogonal each other. We calculate correlations (correlation) between the received signal and the sequences (sequence). Thus, we can estimate a noise power independently. Using the estimated noise power, we can estimate SNR regardless of kinds of fading. Moreover we donpsilat need to use known pilot symbol. We compare the new method with a conventional method by simulation. In this simulation, we also studied the two cases; one orthogonal sequence case and two orthogonal sequences case. As a result, we show the new method can estimate SNR more precisely than the conventional method. Moreover, two orthogonal sequences case could estimate more precisely than one orthogonal sequence case.