CN102612051A - Random access detection method and random access detection device based on time division-long term evolution (TD-LTE) - Google Patents

Abstract

The present invention relates to a random access detection method and device based on TD-LTE, wherein the method includes: frequency division multiplexing a predetermined number of random access preambles of the same preamble format in the received antenna data in the same subframe in the time domain The signal is grouped and down-sampled simultaneously to obtain the down-sampled data sequence; the down-sampled data sequence is subjected to FFT processing and buffered to complete the extraction of the multi-frequency point random access preamble frequency domain sequence. The present invention realizes that in the TDD mode, the grouping of 6 parallel random access signals is simultaneously completed and the down-sampling process is performed at the same time, and the 6 preamble sequences of the occupied frequency domain resources are simultaneously extracted on the corresponding time domain resources, and restored to The sequence of 839 points or 139 points is convoluted and correlated with the corresponding locally generated mother code sequence, and the peak detection is performed on the obtained correlation sequence to obtain detailed information of the peak position, thereby saving the resource overhead of random access detection .

Description

Random access detection method and device based on TD-LTE

technical field

The present invention relates to the communication field, in particular to a random access detection method and device based on TD-LTE (Time Division-Synchronous Code Division Multiple Access Long Term Evolution, Time Division Synchronous Code Division Multiple Access Long Term Evolution).

Background technique

According to the 3GPP TS 36.211 protocol, in TDD (Time Division Duplexing, Time Division Duplexing) mode, the format of the system random access preamble signal in the time domain is shown in Figure 1. The random access sequence of each format consists of one or two preamble (preamble) sequences, and for formats 0, 1, 2, and 3, the length of the preamble is 0.8ms, which consists of a Zadoff-Chu sequence with a length of 839 points produce. For format 4, the length of the preamble is 0.133ms, which is generated by a Zadoff-Chu sequence with a length of 139 points.

In the frequency domain, the spectrum width occupied by a random access preamble is equivalent to 6 RBs, and the corresponding bandwidth is 1.08MHz.

However, since the symbol sampling period defined by the LTE system is 1/30720000s, that is, the sampling frequency is 30.72MHz. Therefore, for the random access preamble, there is serious oversampling. Each preamble of random access formats 0, 1, 2, and 3 has 24576 sampling points, while the preamble of format 4 has 4096 sampling points. In order to reduce the computational complexity, random access first needs to perform a down-sampling operation to reduce the number of sampling points of the received antenna preamble to the order of 839 or 139, and then perform correlation processing with the locally generated cell Zadoff-Chu sequence.

The essence of random access detection is the process of convolution correlation between the received sequence and the local mother code sequence. Due to the high computational complexity of convolution correlation, usually according to its principle, fast Fourier transform (FFT, Fast Fourier Transformation) is used to convert the correlated The sequence is converted to the frequency domain for the dot product operation, and the result is converted to the time domain by an inverse fast Fourier transform (IFFI, Inverse Fast Fourier Transform) to obtain an equivalent result.

According to the 3GPP (The 3rd Generation Partnership Project, 3rd Generation Partnership Project) TS 36.211 protocol, in TDD mode, up to 6 preambles can be connected at the same time, they occupy the same time domain resources, but occupy different frequency band resources, now Some random access detection devices can only process one random access signal at a time, thereby increasing system resource overhead.

Contents of the invention

The main purpose of the present invention is to provide a random access detection method and device based on TD-LTE, aiming at saving resource overhead of random access detection.

In order to achieve the above object, the present invention proposes a random access detection method based on Time Division Synchronous Code Division Multiple Access Long Term Evolution TD-LTE, including:

Grouping a predetermined number of random access preamble time-domain signals of the same preamble format that are frequency division multiplexed in the same subframe in the received antenna data and performing downsampling processing at the same time to obtain a downsampling data sequence;

Perform fast Fourier transform (FFT) processing on the down-sampled data sequence and cache it to complete the extraction of the multi-frequency point random access preamble frequency domain sequence.

Preferably, the predetermined number is 6; when the random access preamble format is 0, 1, 4, the random access preamble time domain signal includes 6 preamble sequences; when the random access preamble format is 2, 3 When , the random access preamble time domain signal includes 12 preamble sequences.

Preferably, the step of grouping a predetermined number of random access preamble time-domain signals of the same preamble format frequency division multiplexed in the same subframe in the received antenna data and performing downsampling processing at the same time, and obtaining the downsampled data sequence includes :

When the format of the random access preamble is 0, 1, or 4, dividing the random access preamble time-domain signal into two groups and simultaneously performing downsampling processing to obtain two sets of downsampling data sequences; or

When the format of the random access preamble is 2 and 3, the random access preamble time domain signal is divided into 4 groups and the downsampling process is performed simultaneously to obtain 4 groups of downsampling data sequences;

The downsampling data sequence is cached.

Preferably, after the step of completing the extraction of the multi-frequency point random access preamble frequency domain sequence, it also includes:

correlating the preamble frequency domain sequence after FFT processing with the local mother code sequence to obtain a correlation sequence;

Carry out inverse Fast Fourier Transform (IFFT) processing of corresponding points to the correlation sequence;

Combining the leading time-domain sequences after the IFFT processing;

The position information of the peak of the combined leading time domain sequence is extracted.

Preferably, the step of correlating the FFT-processed preamble frequency domain sequence with the local mother code sequence to obtain the related sequence includes:

When the preamble format of the preamble frequency domain sequence is 0, 1 or 4, each time a preamble frequency domain sequence is taken out from the data buffer to correlate with the local mother code sequence; or when the preamble of the preamble frequency domain sequence When the format is 2 or 3, two of the preamble frequency domain sequences are taken out from the data cache each time to correlate with the local mother code sequence.

The present invention also proposes a random access detection device based on TD-LTE, including:

The down-sampling module is used to group a predetermined number of random access preamble time-domain signals of the same preamble format that are frequency-division multiplexed in the same subframe in the received antenna data and simultaneously perform down-sampling processing to obtain a down-sampling data sequence;

The FFT module is configured to perform FFT processing on the down-sampled data sequence and cache it, so as to complete the extraction of the multi-frequency point random access preamble frequency domain sequence.

Preferably, the predetermined number is 6; when the random access preamble format is 0, 1, 4, the random access preamble time domain signal includes 6 preamble sequences; when the random access preamble format is 2, 3 When , the random access preamble time domain signal includes 12 preamble sequences.

Preferably, the downsampling module includes:

A packet down-sampling unit, configured to divide the random access preamble time-domain signal into two groups and perform down-sampling processing simultaneously when the random access preamble format is 0, 1, and 4, to obtain two sets of down-sampled data sequences; or When the format of the random access preamble is 2 and 3, the random access preamble time domain signal is divided into 4 groups and the downsampling process is performed simultaneously to obtain 4 groups of downsampling data sequences;

A data cache unit, configured to cache the downsampled data sequence.

Preferably, the device also includes:

A correlation module, configured to correlate the preamble frequency domain sequence after FFT processing with the local mother code sequence, to obtain a correlation sequence;

An IFFT module, configured to perform IFFT processing on the correlation sequence corresponding to the number of points;

A merging module for merging the leading time-domain sequences after IFFT processing;

The peak position information extraction module is used to extract the peak position information of the combined leading time domain sequence.

Preferably, when the preamble format of the preamble frequency domain sequence is 0, 1 or 4, each time one of the preamble frequency domain sequences is taken out from the data cache to correlate with the local mother code sequence; or when the preamble frequency domain sequence When the preamble format of the sequence is 2 or 3, two preamble frequency domain sequences are fetched from the data cache each time to correlate with the local mother code sequence.

A random access detection method and device based on TD-LTE proposed by the present invention realizes the grouping and downsampling of 6 parallel random access signals of frequency division multiplexing in the same subframe at the same time in the TDD mode processing, simultaneously extracting 6 preambles occupying the frequency domain resource on the corresponding time domain resource, and restoring it to a sequence of 839 points or 139 points, performing convolution correlation processing with the corresponding locally generated mother code sequence, and obtaining Peak detection is performed on the relevant sequence of the algorithm, and the detailed information of the peak position is obtained, thereby saving the resource overhead of random access detection.

Description of drawings

FIG. 1 is a schematic diagram of a format of a random access preamble;

Fig. 2 is a schematic flow chart of an embodiment of the TD-LTE-based random access detection method of the present invention;

FIG. 3 is a schematic diagram of packet downsampling in an embodiment of the TD-LTE-based random access detection method of the present invention;

FIG. 4 is a grouping of a predetermined number of random access preamble time-domain signals of the same preamble format that are frequency-division multiplexed in the same subframe in the received antenna data in an embodiment of the TD-LTE-based random access detection method of the present invention. At the same time, the downsampling process is performed to obtain a flow diagram of the downsampling data sequence;

FIG. 5 is a schematic flow chart of another embodiment of the TD-LTE-based random access detection method of the present invention;

6 is a schematic structural diagram of an embodiment of a TD-LTE-based random access detection device according to the present invention;

7 is a schematic structural diagram of a downsampling module in an embodiment of a TD-LTE-based random access detection device according to the present invention;

FIG. 8 is a schematic structural diagram of another embodiment of a TD-LTE-based random access detection device according to the present invention.

In order to make the technical solution of the present invention clearer and clearer, it will be further described below in conjunction with the accompanying drawings.

Detailed ways

The solution of the embodiment of the present invention is mainly to realize the processing of 6 parallel random access signals in the TDD mode at the same time, simultaneously extract the 6 preambles occupying the frequency domain resources on the corresponding time domain resources, and restore them to 839 points Or the 139-point sequence, and the corresponding locally generated Zadoff-Chu sequence, perform convolution correlation processing, and perform peak detection on the obtained correlation sequence to obtain detailed information on the peak position.

As shown in Figure 2, an embodiment of the present invention proposes a random access detection method based on TD-LTE, including:

Step S101, grouping a predetermined number of random access preamble time-domain signals of the same preamble format that are frequency division multiplexed in the same subframe in the received antenna data and performing downsampling processing at the same time to obtain a downsampling data sequence;

In this embodiment, digital spectrum relocation and packet downsampling are simultaneously performed on the six random access preamble time domain signals that need to be performed when random access sequences on different frequency domain resources are simultaneously accessed. Through the packet downsampling operation, the time domain The amount of oversampled preamble data is greatly reduced.

The six channels of random access preamble time domain signals processed in parallel are all in the same preamble format, and the random access preamble time domain signals of each preamble format are composed of 6 preamble sequences or 12 preamble sequences.

Specifically, in the downsampling process, a predetermined number (6 channels in this embodiment) of random access preamble time domain signals are grouped, and when the preamble format of the processed 6 channels of random access preamble time domain signals is 0 , 1 and 4, the random access preamble time-domain signal includes 6 preamble sequences, the random access preamble time-domain signal is divided into 2 groups and the down-sampling process is performed at the same time, and 2 groups of down-sampling sequences are obtained; when the processed 6-way random When the preamble format of the access preamble time-domain signal is 2 and 3, the random access preamble time-domain signal is divided into 4 groups and down-sampling is performed simultaneously to obtain 4 groups of down-sampling sequences. In this way, each group contains 3 leading sequences. In the process of downsampling and subsequent fast Fourier transform, the leading sequences within the group are not distinguished.

For preamble formats 0, 1, 2, and 3, the length of a downsampling sequence is 3072; for preamble format 4, the length of a downsampling sequence is 512. After the downsampling process is completed, all downsampling sequences are cached for data.

Step S102, perform FFT processing on the down-sampled data sequence and buffer it, and complete the extraction of the multi-frequency point random access preamble sequence in the frequency domain.

The 3072-point FFT transformation can be performed on the down-sampled data. Through the FFT transformation, the time-domain convolution correlation process with a large amount of calculation can be converted into the dot product process of the frequency domain sequence.

The down-sampling sequence in the data cache is subjected to FFT transformation once, and the obtained FFT-transformed preamble frequency domain sequence is stored back into the data cache once. Since the downsampling sequence has two lengths of 3072 and 512, the preamble frequency domain sequence also has two lengths, and the preamble frequency domain sequence of 3072 points corresponds to the random access preamble format 0, 1, 2, 3, and the preamble frequency domain of 512 points The sequence corresponds to preamble format 4, and each preamble frequency domain sequence contains frequency domain values of 3 preamble access sequences, and the length is 839 or 139.

Through the above steps S101 and S102, the extraction of access sequences of different frequency domain resources on the same time domain resource on the antenna is completed, and their corresponding frequency domain sequences are obtained. At this time, the counter Pcnt of the number of preamble sequences in the data cache is The number of Pcnt should be 3 times the number of preamble frequency domain sequences.

As shown in Figure 3, when the format of the random access preamble is 0, 1, and 4, as mentioned above, a packet down-sampling process can be performed, and two sets of data sequences can be obtained in the data buffer unit; for the random access preamble Formats 2 and 3, according to the structure shown in Figure 3, perform group down-sampling processing twice, then you can get 4 sets of data sequences in the data cache unit, each of which contains 3 leading sequences.

The data sequences in all groups are sequentially taken out from the data cache unit, and fast Fourier transform is performed, and the obtained output data is stored back into the data cache unit. Among them, the data sequence of a group undergoes a Fourier transform, and the output data obtained is still a group, and the size is the same as that of the input group.

After this operation, each group contains 3 preamble frequency domain sequences, and the 3 preamble frequency domain sequences in the group can be distinguished only by the storage location of the data in the group in the data buffer unit.

It can be seen from this that only two parallel down-sampling processes as shown in FIG. 3 are used to complete the down-sampling operation of up to six random access preamble sequences. Through at most 4 fast Fourier transforms (the preamble formats 2 and 3 are divided into 4 groups), the 12 preamble sequences are transformed into the frequency domain, and a maximum of 12 preamble sequences in the frequency domain are obtained.

As shown in Figure 4, the above step S101 includes:

Step S1011, when the random access preamble format is 0, 1, or 4, divide the random access preamble time domain signal into two groups and perform downsampling processing at the same time to obtain two groups of downsampled data sequences; or when the random access preamble format When it is 2 and 3, divide the random access preamble time domain signal into 4 groups and perform down-sampling processing at the same time, and obtain 4 groups of down-sampling data sequences;

Step S1012, caching the downsampled data sequence.

As shown in Figure 5, another embodiment of the present invention proposes a random access detection method based on TD-LTE, including:

Step S301, grouping a predetermined number of random access preamble time domain signals of the same preamble format that are frequency division multiplexed in the same subframe in the received antenna data and performing downsampling processing at the same time to obtain a downsampling data sequence;

Step S302, perform FFT processing on the down-sampled data sequence and cache it, and complete the extraction of the multi-frequency point random access preamble sequence;

The above step S301 and step S302 are correspondingly the same as the step S101 and step S102 in the above embodiment, and will not be repeated here.

Step S303, correlating the preamble frequency domain sequence after the FFT processing with the local mother code sequence to obtain a correlation sequence;

In order to complete the further detection of the random access preamble time-domain signal, it is necessary to correlate the FFT-processed preamble frequency-domain sequence with the local mother code sequence, so as to perform combination processing and peak detection on the correlated sequences.

Specifically, when the preamble format of the current pilot domain sequence is 0, 1 or 4, each time a preamble domain sequence is taken out from the data buffer to correlate with the local mother code sequence; or the preamble format of the current pilot domain sequence is 2 or 3, take two preamble frequency domain sequences from the data cache each time and correlate with the local mother code sequence. Finally, correlate all the preamble frequency domain sequences in the data buffer with the local mother code sequence.

The correlation process is the process of multiplying the corresponding points, and the obtained sequence of 839 or 139 points length is supplemented with 0 to obtain a correlation sequence of 1536 or 256 points length.

Step S304, performing IFFT processing on the correlation sequence corresponding to the number of points;

Perform 1536-point IFFT transformation on the correlation sequence to obtain the leading time domain sequence.

Step S305, combining the leading time-domain sequences after the IFFT processing;

The IFFT outputs of all antennas are merged. For formats 2 and 3, the two correlation sequences after the antenna merger still need to be merged into one correlation sequence, and then a single correlation sequence is formed, and finally the peak position information can be detected.

Step S306, extracting the peak position information of the combined leading time domain sequence.

Perform peak detection on the combined time domain sequences to find the position information of each peak.

The above process is performed in a pipeline until the Pcnt preamble frequency domain sequences stored in the data buffer are completely processed. Complete random access detection.

This embodiment is aimed at the simultaneous access of random access sequences on different frequency domain resources in the TDD mode to group 6 random access preamble time domain sequences and simultaneously perform downsampling processing, as well as fast Fourier transform and inverse transform processing In the process, only through the two-way parallel down-sampling process shown in Figure 3, the down-sampling operation of up to 6 random access preamble sequences has been completed, and at most 4 fast Fourier transforms (preamble formats 2 and 3 are divided into 4 groups), the 12 preamble sequences are transformed into the frequency domain, and a maximum of 12 preamble frequency domain sequences are obtained, so that the special processing of random access under TD-LTE is realized through low resource overhead.

As shown in FIG. 6, an embodiment of the present invention proposes a TD-LTE-based random access detection device, including: a downsampling module 401 and an FFT module 402, wherein:

The down-sampling module 401 is used to group a predetermined number of random access preamble time-domain signals of the same preamble format that are frequency-division multiplexed in the same subframe in the received antenna data and simultaneously perform down-sampling processing to obtain a down-sampling data sequence;

In this embodiment, digital spectrum relocation and packet downsampling are simultaneously performed on the six random access preamble time domain signals that need to be performed when random access sequences on different frequency domain resources are simultaneously accessed. Through the packet downsampling operation, the time domain The amount of oversampled preamble data is greatly reduced.

The six random access preamble time domain signals processed in parallel are all in the same preamble format, and the random access preamble time domain signals of each preamble format are composed of 6 preamble sequences or 12 preamble sequence sequences.

Specifically, in the downsampling process, a predetermined number (6 channels in this embodiment) of random access preamble time domain signals are grouped, and when the preamble format of the processed 6 channels of random access preamble time domain signals is 0 , 1 and 4, the random access preamble time-domain signal includes 6 preamble sequences, the random access preamble time-domain signal is divided into 2 groups and the down-sampling process is performed at the same time, and 2 groups of down-sampling sequences are obtained; when the processed 6-way random When the preamble format of the access preamble time-domain signal is 2 and 3, the random access preamble time-domain signal is divided into 4 groups and down-sampling is performed simultaneously to obtain 4 groups of down-sampling sequences. In this way, each group contains 3 leader sequences. In the process of downsampling and subsequent fast Fourier transform, the leading sequences within the group are not distinguished.

For preamble formats 0, 1, 2, and 3, the length of a downsampling sequence is 3072; for preamble format 4, the length of a downsampling sequence is 512. After the downsampling process is completed, all downsampling sequences are cached for data.

The FFT module 402 is configured to perform FFT processing on the downsampled data sequence and buffer it, and complete the extraction of the multi-frequency point random access preamble.

The 3072-point FFT transformation can be performed on the down-sampled data. Through the FFT transformation, the time-domain convolution correlation process with a large amount of calculation can be converted into the dot product process of the frequency domain sequence.

The down-sampling sequence in the data cache is sent to the FFT module 402 once for FFT transformation, and the obtained FFT-transformed preamble frequency domain sequence is stored back into the data cache once. Since the downsampling sequence has two lengths of 3072 and 512, the preamble frequency domain sequence also has two lengths, and the preamble frequency domain sequence of 3072 points corresponds to the random access preamble format 0, 1, 2, 3, and the preamble frequency domain of 512 points The sequence corresponds to preamble format 4, and each preamble frequency domain sequence contains frequency domain values of 3 preamble access sequences, and the length is 839 or 139.

Through the above process, the extraction of different frequency domain resource access sequences on the same time domain resource on the antenna is completed, and their corresponding frequency domain sequences are obtained. At this time, the number counter Pcnt of the preamble sequence in the data cache, the number of Pcnt should be It is three times the number of preamble frequency domain sequences.

As shown in Figure 3, when the format of the random access preamble is 0, 1, and 4, as mentioned above, a packet down-sampling process can be performed, and two sets of data sequences can be obtained in the data buffer unit; for the random access preamble Formats 2 and 3, according to the structure shown in Figure 3, perform group down-sampling processing twice, then you can get 4 sets of data sequences in the data cache unit, each of which contains 3 leading sequences.

The data sequences in all groups are sequentially taken out from the data cache unit, and fast Fourier transform is performed, and the obtained output data is stored back into the data cache unit. Among them, the data sequence of a group undergoes a Fourier transform, and the output data obtained is still a group, and the size is the same as that of the input group.

After this operation, each group contains 3 preamble frequency domain sequences, and the 3 preamble frequency domain sequences in the group can be distinguished only by the storage location of the data in the group in the data buffer unit.

It can be seen from this that only two parallel down-sampling processes as shown in FIG. 3 are used to complete the down-sampling operation of up to six random access preamble sequences. Through at most 4 fast Fourier transforms (the preamble formats 2 and 3 are divided into 4 groups), the 12 preamble sequences are transformed into the frequency domain, and a maximum of 12 preamble sequences in the frequency domain are obtained.

As shown in Figure 7, the down-sampling module 401 includes: a packet down-sampling unit 4011 and a data cache unit 4012, wherein:

The packet down-sampling unit 4011 is used to divide the random access preamble time-domain signal into two groups and perform down-sampling processing simultaneously when the random access preamble format is 0, 1, and 4, so as to obtain two groups of down-sampling data sequences; or when When the format of the random access preamble is 2 or 3, the random access preamble time-domain signal is divided into 4 groups and down-sampled simultaneously to obtain 4 groups of down-sampled data sequences;

The data cache unit 4012 is configured to cache the downsampled data sequence.

As shown in Figure 8, another embodiment of the present invention proposes a random access detection device based on TD-LTE, including: downsampling module 501, FFT module 502, correlation module 503, IFFT module 504, combining module 505 and peak Location information extraction module 506, wherein:

The down-sampling module 501 is configured to group a predetermined number of random access preamble time-domain signals of the same preamble format that are frequency-division multiplexed in the same subframe in the received antenna data and simultaneously perform down-sampling processing to obtain a down-sampling data sequence;

The FFT module 502 is configured to perform FFT processing on the down-sampled data sequence and buffer it, and complete the extraction of the multi-frequency point random access preamble.

The down-sampling module 501 and the FFT module 502 have the same function and structure as the down-sampling module 401 and the FFT module 402 in the above-mentioned embodiment, and will not be repeated here.

A correlation module 503, configured to correlate the FFT-processed preamble frequency domain sequence with the local mother code sequence to obtain a correlation sequence;

In order to complete the further detection of the random access preamble time-domain signal, this embodiment correlates the FFT-processed preamble frequency-domain sequence with the local mother code sequence through the correlation module 503, so as to perform combination processing and peak detection on the correlated sequences.

Specifically, when the preamble format of the current pilot domain sequence is 0, 1 or 4, each time a preamble domain sequence is taken out from the data buffer to correlate with the local mother code sequence; or the preamble format of the current pilot domain sequence is 2 or 3, take two preamble frequency domain sequences from the data cache each time and correlate with the local mother code sequence. Finally, correlate all the preamble frequency domain sequences in the data buffer with the local mother code sequence.

The correlation process is the process of multiplying the corresponding points, and the obtained sequence of 839 or 139 points length is supplemented with 0 to obtain a correlation sequence of 1536 or 256 points length.

The IFFT module 504 is used to perform IFFT processing on the correlation sequence corresponding to the number of points;

Perform 1536-point IFFT transformation on the correlation sequence to obtain the leading time domain sequence.

A merging module 505, configured to perform merging processing on the leading time-domain sequence after IFFT processing;

The merging module 505 merges the IFFT outputs of all antennas. For formats 2 and 3, the two correlation sequences after antenna merging still need to be merged into one correlation sequence, and then form a single-path correlation sequence, and finally the peak position information can be extracted. detection.

The peak position information extraction module 506 is configured to extract the peak position information of the combined leading time domain sequence.

The peak position information extraction module 506 performs peak detection on the combined time domain sequence to find the position information of each peak.

The above process is performed in a pipeline until the Pcnt preamble frequency domain sequences stored in the data buffer are completely processed. Complete random access detection.

The embodiment of the present invention is based on the random access detection method and device of TD-LTE, and realizes the grouping of 6 parallel random access preamble time domain signals and simultaneous down-sampling processing in TDD mode, as well as fast Fourier transform and In the process of inverse transformation, 6 preambles occupying frequency domain resources are simultaneously extracted on the corresponding time domain resources, and restored to a sequence of 839 points or 139 points, and the corresponding locally generated mother code sequence is subjected to convolution correlation processing. And perform peak detection on the obtained correlation sequence to obtain the detailed information of the peak position, only through the two-way parallel down-sampling process shown in Figure 3, the down-sampling operation of up to six random access preamble sequences is completed, and Through at most 4 fast Fourier transforms (the preamble formats 2 and 3 are divided into 4 groups), the 12 preamble sequences are transformed into the frequency domain, and a maximum of 12 preamble sequences in the frequency domain are obtained, thereby saving the cost of random access detection. resource overhead.

The above is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields , are all included in the scope of patent protection of the present invention in the same way.

Claims (10)

1. A random access detection method based on Time Division Synchronous Code Division Multiple Access Long Term Evolution TD-LTE, characterized in that, comprising: Grouping a predetermined number of random access preamble time-domain signals of the same preamble format that are frequency division multiplexed in the same subframe in the received antenna data and performing downsampling processing at the same time to obtain a downsampling data sequence; Perform fast Fourier transform (FFT) processing on the down-sampled data sequence and cache it to complete the extraction of the multi-frequency point random access preamble frequency domain sequence. 2. The method according to claim 1, wherein the predetermined number is 6; when the random access preamble format is 0, 1, 4, the random access preamble time domain signal includes 6 preambles Sequence: when the format of the random access preamble is 2 or 3, the random access preamble time domain signal includes 12 preamble sequences. 3. The method according to claim 2, wherein the grouping of random access preamble time-domain signals of the same preamble format and frequency division multiplexing in the same subframe in the received antenna data is carried out simultaneously. Downsampling processing, the steps of obtaining the downsampling data sequence include: When the format of the random access preamble is 0, 1, or 4, dividing the random access preamble time-domain signal into two groups and simultaneously performing downsampling processing to obtain two sets of downsampling data sequences; or When the format of the random access preamble is 2 and 3, the random access preamble time domain signal is divided into 4 groups and the downsampling process is performed simultaneously to obtain 4 groups of downsampling data sequences; The downsampling data sequence is cached. 4. The method according to claim 3, characterized in that, after the step of completing the extraction of the multi-frequency point random access preamble sequence in the frequency domain, it also includes: correlating the preamble frequency domain sequence after FFT processing with the local mother code sequence to obtain a correlation sequence; Carry out inverse Fast Fourier Transform (IFFT) processing of corresponding points to the correlation sequence; Combining the leading time-domain sequences after the IFFT processing; The position information of the peak of the combined leading time domain sequence is extracted. 5. The method according to claim 4, characterized in that, correlating the preamble frequency domain sequence after the FFT processing with the local mother code sequence, and obtaining the step of the correlation sequence comprises: When the preamble format of the preamble frequency domain sequence is 0, 1 or 4, each time a preamble frequency domain sequence is taken out from the data buffer to correlate with the local mother code sequence; or when the preamble of the preamble frequency domain sequence When the format is 2 or 3, two of the preamble frequency domain sequences are taken out from the data cache each time to correlate with the local mother code sequence. 6. A random access detection device based on TD-LTE, characterized in that, comprising: The down-sampling module is used to group a predetermined number of random access preamble time-domain signals of the same preamble format that are frequency-division multiplexed in the same subframe in the received antenna data and simultaneously perform down-sampling processing to obtain a down-sampling data sequence; The FFT module is configured to perform FFT processing on the down-sampled data sequence and cache it, so as to complete the extraction of the multi-frequency point random access preamble frequency domain sequence. 7. The device according to claim 6, wherein the predetermined number is 6; when the random access preamble format is 0, 1, 4, the random access preamble time domain signal includes 6 preambles Sequence: when the format of the random access preamble is 2 or 3, the random access preamble time domain signal includes 12 preamble sequences. 8. The device according to claim 7, wherein the downsampling module comprises: A packet down-sampling unit, configured to divide the random access preamble time-domain signal into two groups and perform down-sampling processing simultaneously when the random access preamble format is 0, 1, and 4, to obtain two sets of down-sampling data sequences; or When the format of the random access preamble is 2 and 3, the random access preamble time domain signal is divided into 4 groups and the downsampling process is performed simultaneously to obtain 4 groups of downsampling data sequences; A data cache unit, configured to cache the downsampled data sequence. 9. The device according to claim 8, further comprising: A correlation module, configured to correlate the preamble frequency domain sequence after FFT processing with the local mother code sequence, to obtain a correlation sequence; An IFFT module, configured to perform IFFT processing on the correlation sequence corresponding to the number of points; A merging module for merging the leading time-domain sequences after IFFT processing; The peak position information extraction module is used to extract the peak position information of the combined leading time domain sequence. 10. The device according to claim 9, wherein when the preamble format of the preamble frequency domain sequence is 0, 1 or 4, each time the preamble frequency domain sequence and the local mother code sequence; or when the preamble format of the preamble frequency domain sequence is 2 or 3, take out two of the preamble frequency domain sequences from the data cache each time and perform correlation with the local mother code sequence.

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