After the NBP protector sees the correlation value spike, many erroneous bits in the first preamble means that it is very likely that some other simultaneous transmission exists.
Our proposed method of pre-backoff is used to spread the first preamble transmissions.
Upon receiving the paging message, P P M UEs will immediately perform a uniform backoff before transmitting their first preamble.
The total number of UEs that transmit their first preamble in the ith RA slot, M i [ 1], is derived in (2).
Here, r i [k] is the sample of the received signal from i th antenna taken within the duration of the first preamble bit t1bit.
The pre-backoff may postpone the transmission time of the first preamble up to the pre-backoff window, W PBO. The group paging interval is given in (1).
Instead of performing paging consecutively, the method proposed in this paper spreads the first preamble transmission by using a pre-backoff mechanism to increase the success probability with lower access delay compared with the original group paging.
Based on the estimation of the first preamble symbol, a coarse estimation of the CFO, which still suffers from intercarrier and intersymbol interference, can be obtained: ν ̂ = 1 2 π ∠ ∑ k ∈ K 2 b ~ k, 2 b ~ k, 0 ∗.
By comparison, in his golfing lesson for Ralph Kramden, Ed Norton committed nine waggles (which were augmented with swiveling hips and swiveling knees) during his 15-second preamble to an exemplary smooth swing executed at Bensonhurst State Park's dilapidated Icebox Course.
The function of the second preamble is to help the receiver detect the CFO, OFDMA user segment deployment, and collision.
