CN102843747B - The signaling method of a kind of synchronizing channel, broadcast channel and UE cut-in method - Google Patents

Abstract

The present invention provides a signal transmission method of a synchronization channel and a broadcast channel under a discrete spectrum system and a UE access method, comprising: at a preset position in each cluster frequency band of the discrete spectrum system, transmitting the synchronization channel and the broadcast channel A signal of a broadcast channel; the UE receives a signal of a synchronization channel and a broadcast channel on each cluster of the discrete spectrum system, and selects a cluster with the best signal to reside in and initiate access according to the received signal. Through the present invention, the detection probability of synchronization and broadcast channels can be improved, and the access probability of UE can be effectively improved.

Description

A signal transmission method of a synchronization channel and a broadcast channel, and a UE access method

technical field

The present invention relates to a synchronization channel and a broadcast channel technology in a communication system, in particular to a signal transmission method and a UE access method of a synchronization channel and a broadcast channel under a discrete spectrum system.

Background technique

At present, the 230MHz frequency band is mainly used in data transmission stations to undertake remote data collection work. Because the provided rate is very low, it can only be used for some simple communication applications, and cannot meet the growing business needs of smart grids and sensor networks. According to the future planning of the State Grid, it is required to find a new broadband communication technology to meet the business needs of its distribution network automation, load management, electricity consumption information collection, smart grid user services, emergency repairs, and video surveillance in special areas.

The 230MHz frequency band product based on TD-LTE technology provides a better solution for the above needs. This product inherits the advantages of OFDM's orthogonal multi-subcarrier transmission, relatively flat channel and relatively small intersymbol crosstalk. Taking advantage of the ease of scalability, frequency selectivity, and scheduling flexibility of the OFDMA system, and creatively absorbing advanced communication concepts such as carrier aggregation and spectrum sensing, it forms a new generation of low-power, high-spectrum utilization, and high-reliability Flexible multi-service communication system. It can meet the business requirements of the power load monitoring system to the greatest extent, and at the same time provide a solid technical accumulation and application demonstration for the next generation network planning of the State Grid.

In the existing OFDM communication system, the synchronization channel and the broadcast channel are set in a continuous frequency band for signal transmission, as shown in FIG. 1 . However, when using multiple (cluster) discrete frequency bands for communication, if the broadcast channel is only designed in one cluster of frequency bands, then when this continuous channel is strongly interfered, the UE cannot search for the synchronization channel, nor can it complete cell parking. stay, and cannot receive broadcast channel information.

Contents of the invention

The invention provides a signal sending method of the synchronous channel and the broadcast channel under the discrete spectrum system, which can improve the detection probability of the synchronous channel and the broadcast channel.

At the same time, the present invention also provides a UE access method under the discrete frequency spectrum system, which can effectively improve the UE access probability.

To achieve the above object, the present invention adopts the following technical solutions:

A signal transmission method of a synchronization channel and a broadcast channel under a discrete spectrum system, comprising:

Signals of the synchronization channel and the broadcast channel are sent at preset positions in each cluster frequency band of the discrete spectrum system.

Preferably, the preset positions in each cluster frequency band are the same.

Preferably, the preset position in each cluster frequency band is: on the middle sub-band of the corresponding cluster frequency band.

Preferably, the signals of the synchronization channel and the broadcast channel are sent alternately in time on the same sub-band.

The method for performing UE access according to the signal sent according to the above method includes:

The UE receives signals of the synchronization channel and the broadcast channel on each cluster of the discrete spectrum system, and selects a cluster with the best signal to reside in according to the received signals.

Preferably, the UE receives signals of the synchronization channel and the broadcast channel on each cluster as follows:

The subband numbers where the synchronization channel and broadcast channel signals in each cluster are located are pre-configured on the UE, and the UE receives the synchronization channel and broadcast channel signals on corresponding subbands according to the configured subband numbers.

Preferably, the UE receives signals of the synchronization channel and the broadcast channel on each cluster as follows:

The UE performs blind detection on the subbands of each cluster, and receives signals of the synchronization channel and the broadcast channel.

Preferably, when the number of access users on any cluster frequency band of the discrete spectrum system exceeds a preset threshold, a busy flag is set in the broadcast channel signal of any cluster;

When the UE accesses, set the cluster whose busy flag is set as the lowest access priority.

Preferably, when the UE cannot access other clusters or cells except the cluster with the busy flag set, the UE accesses the cluster with the busy flag set, and the eNodeB performs unified resource scheduling.

It can be seen from the above technical solution that in the present invention, at the preset position in each cluster frequency band of the discrete spectrum system, the signals of the synchronization channel and the broadcast channel are sent; the UE receives the synchronization channel on each cluster of the discrete spectrum system and broadcast channel signals, and according to the received signals, select a cluster with the best signal to reside and initiate access. In this way, since the synchronization channel and broadcast channel are sent in each cluster frequency band of the discrete spectrum system, even if some of the clusters are strongly interfered and cannot be detected, the UE can still receive the synchronization channel and broadcast channel in other clusters, thereby improving the frequency range of the synchronization channel. and the detection probability of the broadcast channel, effectively improving the access probability of the UE.

Description of drawings

FIG. 1 is a schematic diagram of sending a synchronization channel and a broadcast channel in the prior art;

Fig. 2 is the setting schematic diagram of synchronous channel and broadcast channel among the present invention;

FIG. 3 is a schematic diagram of signal transmission of a synchronization channel and a broadcast channel in the present invention.

detailed description

In order to make the purpose, technical means and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

The present invention provides a signal transmission method of a synchronization channel and a broadcast channel under a discrete spectrum system, and further provides a method for UE access according to the transmitted synchronization and broadcast channel signals. Next, the specific implementation of the present invention will be described in detail.

The signal transmission method of the synchronization channel and the broadcast channel of the present invention includes: in the cell of the discrete spectrum system, pre-specify the position used for transmitting the synchronization channel and the broadcast channel in each cluster, and at the pre-designated position in each cluster The signals of the synchronization channel and the broadcast channel are sent, and the signals transmitted on the synchronization channel and the broadcast channel in each cluster are the same.

After the signals of the synchronization channel and the broadcast channel are transmitted according to the above method, the method for performing UE access according to the transmitted signal includes: the UE receives the signals of the synchronization channel and the broadcast channel on each cluster, and selects the best signal according to the received signal A good cluster resides and initiates access.

In the signal transmission method of the synchronization and broadcast channel and the UE access method described above, when the UE receives the signals of the synchronization channel and the broadcast channel, it may use a blind detection method or store synchronization and broadcast channel information in the UE in advance. .

Specifically, in the blind detection method, the UE does not know the specific locations of the synchronization channel and the broadcast channel in each cluster frequency band in advance, and the UE performs blind detection on each subband in each cluster frequency band when accessing. The synchronization and broadcast channels are searched, and when the synchronization and broadcast channels are found, the corresponding signals are received, and compared with the corresponding signals in each cluster frequency band, a cluster with the best signal is selected to reside and initiate access. In this manner, the UE does not need additional storage space to save the location information of the synchronization and broadcast channels, saving storage resources in the UE.

However, when receiving signals by storing the synchronization and broadcast channel information in the UE in advance, it is necessary to save the subband number of the synchronization and broadcast channel in each cluster frequency band in the UE in advance. When the UE accesses, it directly The sub-band number of the corresponding sub-band is used to receive the signals of the synchronization channel and the broadcast channel; and compare the corresponding signals in each cluster frequency band, and select a cluster with the best signal for access. In this way, the UE can directly determine the information of the synchronization and broadcast channels, and does not need to search for the synchronization and broadcast channels one by one subband, which can save processing time; however, it needs to consume the storage space on the UE to save the information of the synchronization and broadcast channels location information.

In the signal transmission method of the above-mentioned synchronous and broadcast channel, when specifying the bearing position for the synchronous and broadcast channel in advance, the synchronous and broadcast channels in each cluster frequency band can be designated on the same position, and the same position here means that the corresponding channel is in the same position. The relative positions in the frequency bands of the cluster, for example, designate the middle sub-bands of the frequency bands of each cluster for transmitting signals of synchronization and broadcast channels. In this way, since the positions of the synchronization and broadcast channels in each cluster frequency band are the same, when the UE accesses, if the synchronization and broadcast channel signals are received by blind detection, the synchronization and broadcast channel signals are detected in the first cluster frequency band. After channeling, it is enough to receive the synchronization and broadcast channel at the same position of other cluster frequency bands, and there is no need to detect the synchronization and broadcast channel signals subband by subband.

More preferably, if the middle sub-band of each cluster frequency band is designated to transmit signals of synchronization and broadcast channels, when the UE accesses, it may switch from the resident sub-band (middle sub-band) to other sub-bands for business communication , the method of placing the synchronization and broadcast channels in this way will reduce the amplitude of the frequency point span when the UE accesses, thereby reducing the frequency offset caused by frequency point adjustment. Among them, when a cluster of frequency bands includes an even number of subbands, the middle subband can be defined as or N is the number of subbands.

Take three discrete cluster frequency bands as an example for illustration. As shown in Figure 2, three discrete cluster frequency bands are respectively distributed in 223.025-228.000MHz, 228.025-230.000MHz and 230.025-235.000MHz. There are 15, 10 and 15 sub-bands in each of the three cluster frequency bands. Synchronization and broadcast channels are set inside. Synchronization and broadcast signals are sent in the middlemost sub-band of each cluster frequency band, which can reduce the frequency point crossing range of UE access, thereby reducing the frequency offset caused by frequency point adjustment. The default position of the broadcast of the first cluster and the third cluster is the 8th sub-band (7 sub-bands on the left and right), and the broadcast position of the second cluster is located on the 5th sub-band (5 sub-bands on one side and 4 sub-bands on the other side).

When sending the signals of the synchronization and broadcast channels, they can be sent in an existing manner, that is, the signals of the synchronization and broadcast channels are sent in the same subframe. Preferably, since the discrete spectrum system is generally a narrowband communication system with limited resources, in order to save more resources for transmitting service data, the synchronization channel and the broadcast channel can be sent alternately in time on the same subband, that is, in the same subband On adjacent subframes, the synchronization channel signal and the broadcast channel signal are sent in turn, and the signal transmission mode taking the synchronization and broadcast channel of the OFDM system as an example is shown in FIG. 3 .

In addition, when the UE accesses the discrete spectrum system, as mentioned above, a cluster with the best signal is selected in each cluster frequency band for access. However, considering that the discrete spectrum system is generally a resource-constrained narrowband communication system, the number of resident users on a cluster is limited. Therefore, preferably, when sending broadcast channel signals, if the number of access users on a certain cluster frequency band When the preset threshold is exceeded, the busy flag is set in the broadcast channel signal of the cluster frequency band, and when the UE accesses, the access priority of the cluster frequency band with the busy flag set is set to the lowest. Wherein, the preset threshold may be determined according to parameters such as system bandwidth and number of access users. If the UE cannot access other clusters whose busy flag is not set or cannot access other cells, then the UE can still access a cluster whose busy flag is set, and the eNodeB uniformly schedules resources to accommodate the UE. In this way, on the one hand, the number of resident users of each cluster can be coordinated, and on the other hand, the access probability of the UE can be improved.

The above is the signal transmission method of the synchronization channel and the broadcast channel and the UE access method in the present invention. The detection probability of the synchronization and broadcast channel is improved by setting multiple identical synchronization and broadcast channels. That is, a synchronization channel and a broadcast channel are set in each discrete cluster frequency band, and the UE can search for the synchronization channel and broadcast channel in each cluster, thereby completing cell camping and receiving broadcast information. The method of the present invention has good anti-interference characteristics. When there is strong interference in multiple clusters, as long as one cluster is not subjected to strong interference, the UE can still complete the reception of the synchronization channel and the broadcast channel, thereby improving the UE's ability to search for Probability of sync channel and broadcast channel. At the same time, the method of the present invention performs synchronization and transmission of broadcast channels at specific positions (such as the middle sub-band) of each cluster, which can reduce the amplitude of the frequency point span caused by reading broadcast channels in different clusters, and reduce the frequency point Frequency offset caused by adjustment.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (9)

1. a signal transmission method of a synchronous channel and a broadcast channel under a discrete spectrum system, characterized in that the method comprises: Signals of the synchronization channel and the broadcast channel are sent at preset positions in each cluster frequency band of the discrete spectrum system. 2. The method according to claim 1, wherein the preset positions in each cluster frequency band are the same. 3. The method according to claim 2, wherein the preset position in each cluster frequency band is: on the middle sub-band of the corresponding cluster frequency band. 4. The method according to claim 1, wherein the signals of the synchronization channel and the broadcast channel are sent alternately in time on the same subband. 5. The method for performing UE access according to the signal sent by the method according to any one of claims 1 to 4, characterized in that the method comprises: The UE receives signals of the synchronization channel and the broadcast channel on each cluster of the discrete spectrum system, and selects a cluster with the best signal to reside in according to the received signals. 6. The method according to claim 5, wherein the UE receives signals of the synchronization channel and the broadcast channel on each cluster as follows: The subband numbers where the synchronization channel and broadcast channel signals in each cluster are located are pre-configured on the UE, and the UE receives the synchronization channel and broadcast channel signals on corresponding subbands according to the configured subband numbers. 7. The method according to claim 5, wherein the UE receives signals of the synchronization channel and the broadcast channel on each cluster as follows: The UE performs blind detection on the subbands of each cluster, and receives signals of the synchronization channel and the broadcast channel. 8. The method according to claim 5, characterized in that, when the number of access users on any cluster frequency band of the discrete spectrum system exceeds a preset threshold, a busy flag will be set in the broadcast channel signal of any cluster Position; When the UE accesses, set the cluster whose busy flag is set as the lowest access priority. 9. The method according to claim 8, wherein, when the UE cannot access other clusters or cells except the cluster with the busy flag set, the UE accesses the cluster with the busy flag set, and the eNodeB Perform unified resource scheduling.