Method for dynamic adjusting leading detection threshold of access

Abstract

The method includes: a) presets a threshold T1 of preamble detection false alarm probability P1 as the lowest threshold of the threshold T; b) determines the probability threshold P2 making the lack of demodulation resource in term of the preamble detection false alarm probability P1, and periodically counts the preamble detection probability P3 in a certain period for user; c) decides if the P3 is more than P2; if yes, tunes the T into T' in term of the ratio of P3 to P2; otherwise tunes the T into T' in term of the ratio of P3 to P2; the T' and T' are the current preamble detection threshold varied along with the ratio of P3 to P2.

Description

technical field [0001] The invention relates to a method for adjusting a detection threshold, in particular to a method for dynamically adjusting an access preamble detection threshold. Background technique [0002] In communication technology, user equipment (UE, User Equipment) establishes an initial connection with a base station through a Physical Random Access Channel (PRACH, Physical Random Access Channel), and requests to establish a dedicated channel or send a limited uplink data packet. The structure diagram of the physical random access channel PRACH is as follows figure 1 As shown, including one or more preamble (Preamble) signals (such as figure 1 1 in) and a message (Message) signal (such as figure 1 shown in 3). The length of the preamble signal is 4096 chips, and 16 orthogonal signatures (Signature) can form 16 kinds of preamble signals. In order to reduce access conflicts, the user equipment UE can randomly select according to the signature assigned by the...

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Problems solved by technology

[0009] To sum up, the disadvantages of the prior art are: (1) the setting of the fixed threshold cannot ensure the constant probability of false alarm in the actual application environment, thus failing to meet the requirements of the system; (2) the effective utilization rate of message demodulation resources is reduced; (3) If the fixed detection threshold is increased, although the false alarm is still low when there is an interference signal, the detection probability of the user access signal decreases significantly when there is no interference signal, which leads to an increase in the energy of the user equipment sending the preamble signal, System interference also increases

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