Probability of Miss Analysis for Packet CDMA Acquisition on RicianFading Channels.pdfVIP

IEEE COMMUNICATIONS LETTERS, VOL. 2, NO. 7, JULY 1998 177 Probability of Miss Analysis for Packet CDMA Acquisition on Rician-Fading Channels A. Chockalingam, Member, IEEE , and Gang Bao, Member, IEEE Abstract— We analyze the probability of miss in the acquisi- at the base station. The search space is partitioned into several tion of direct sequence spread-spectrum packets transmitted on frequency bins and discrete time offsets. Let be the number Rician-fading channels. The results are useful to compute the of frequency bins and be the number of discrete time probability of a random-access packet success, and the expected number of packet transmissions needed to achieve success, on offsets. The total number of hypotheses searched is . LEO satellite code-division multiple-access channels. In each hypothesis, the searcher at the base station performs chip coherent integrations of the obtained energy, and Index Terms— Acquisition, packet CDMA, Rician fading. noncoherent accumulations of such coherent integrations. To I. INTRODUCTION simplify the analysis, a packet is considered to be acquired if the correct hypothesis happens to be the one with the largest N DIRECT-SEQUENCE code-division multiple-access energy among all possible hypotheses.