Patent ID: 7301931

Claim:
A hexanary-feedback contention access (HFCA) method with probability density function (pdf) based multi-user estimation for a wireless communication network, which generates a registrable mobile station when a plurality of mobile stations concurrently request for registration in the wireless communication network at a slot, wherein the wireless communication network has at least one base station capable of distinguishing at most 5 mobile stations concurrently requesting for registration and notifies each mobile station of mobile station quantity detected via a downlink, the method comprising the steps: (A) using a random procedure to determine whether or not each mobile station to be registered is allowed proceeding contention access at a subsequent slot, wherein the quantity of mobile stations capable of proceeding contention access at the subsequent slot is defined as a current mobile station quantity; (B) detecting the current mobile station quantity by the base station, and performing step (C) if the current mobile station quantity ranges from 2 to 5 and performing step (A) if the mobile station quantity is 1, wherein the base station implements an estimation method for detecting the mobile station quantity by means of pre-stored pdf distribution curves of 1 to 5 mobile stations concurrently requesting for registration in the wireless communication network, and the estimation method comprises the steps of: (B1) computing an envelope of a signal received by the base station; (B2) deriving a distribution curve of probability density function (pdf) from the envelope; and (B3) matching the distribution curve with the pre-stored pdf distribution curves for goodness-of-fit to estimate the mobile station quantity currently requesting for registration in the wireless network; (C) performing a random procedure based on the current mobile station quantity to determine whether or not a contention access is proceeded at a new subsequent slot for each current mobile station; (D) detecting a mobile station quantity by the base station, and if the detected mobile station quantity is 1, allowing the solely detected mobile station for registration and then reducing the current mobile station quantity by 1; and (E) performing step (A) if the current mobile station quantity is 0, otherwise, performing step (C).