Method and device for detecting random access signal in orthogonal frequency division multiplexing system

Abstract

The invention discloses a method for detecting a random access signal in an orthogonal frequency division multiplexing system. The method comprises the following steps of: converting the random access signal received by an antenna into a frequency domain signal and performing dot product with a conjugate of a frequency domain mother code, converting the dot product result into a time domain signal, and solving modulus square of the converted time domain signal so as to obtain a related sequence; solving the mean value of the related sequence, and using a reciprocal of the mean value as an indirect weight factor of the related sequence; determining the maximum or minimum in indirect weight factors of the related sequence for all the random access signals received by the antenna, and calculating the weight factor of each antenna according to the maximum or minimum of the indirect weight factors; multiplying the related sequence of each antenna with a corresponding weight factor thereof and merging to acquire the weighted and merged related sequence, and detecting the random access signal according to the weighted and merged related sequence. The invention simultaneously discloses a device for the method. The detection performance for the random access signal is improved.

Description

technical field [0001] The present invention relates to a random access signal detection technology, in particular to a random access signal detection method and device in an Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) system. Background technique [0002] OFDM is actually a kind of multi-carrier modulation (MCM, Multi-Carrier Modulation). The resulting orthogonal signals can be separated by using correlation techniques at the receiving end, which can reduce the mutual interference between sub-channels. The signal bandwidth on each sub-channel is smaller than its sub-channel bandwidth, so the signal waveform on each sub-channel can be regarded as flat fading, so that inter-symbol interference can be eliminated. And since the signal bandwidth on each sub-channel is only a fraction of the original channel bandwidth, channel equalization becomes relatively easy. Therefore, during the evolution of the wireless communication sys...

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Problems solved by technology

[0004] In the existing OFDM system, it is not feasible for the random access signal to rely on the signal-to-interference ratio (SIR, Signal toInterference Ratio) to achieve the maximum ratio combination (MRC, Maximum Ration Combining) of multi-antenna data, because the random access signal cannot be obtained Corresponding SIR information

In this way, when the channel quality is poor, the detection performance of the random access signal will be quite poor, which is quite unfavorable for UE access

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