Channel-Adaptive Random Access for TDD-Based Wireless Systems

Security Analysis of Random Access Schemes

“…With channel-adaptive random access, after estimating uplink channel condition, a remote station transmits a random access packet only when the channel condition is greater than predetermined threshold th [3].…”

“…With channel-adaptive random access, since a remote station has a knowledge of channel condition, the transmission power can be a function of . In this paper, constant power allocation ( ) and channel inversion power allocation ( ) are considered [3] and these are expressed as…”

“…When it is assumed that a remote station transmitted a random access packet with channel-adaptive random access, the pdf ′ ( ′ ) of equivalent main small-scale channel gain ′ is obtained as in [3]. When a remote station transmitted a random access packet, the security capacity for constant , and channel inversion power allocation , are computed as…”

“…To reduce transmission energy consumption for random access, channel-adaptive random access is proposed in TDD (time-division-duplex) wireless communication systems [3]. With channel-adaptive random access, since a remote station can estimate uplink channel condition by measuring downlink channel condition by channel reciprocity [4], a remote station transmits a random access packet only when the channel gain is greater and equal to a pre-determined threshold.…”

“…If the channel gain is less than the threshold, a remote station waits to transmit until the channel gain becomes greater or equal than the threshold. There are several researches about channel-adaptive random access [3], [5]- [7]. However, security of channel-adaptive random access has not been investigated.…”