WO2016050072A1

WO2016050072A1 - Rach coverage enhancement method and related device

Info

Publication number: WO2016050072A1
Application number: PCT/CN2015/078824
Authority: WO
Inventors: 肖洁华
Original assignee: 华为技术有限公司
Priority date: 2014-09-30
Filing date: 2015-05-13
Publication date: 2016-04-07
Also published as: CN104284442B; CN104284442A

Abstract

Disclosed are an RACH coverage enhancement method and a related device, which aim to reduce the waste of time resources, increase the resource utilization rate, and improve the coverage performance of an RACH. In some feasible implementation modes of the present invention, the method comprises: mapping a channel request message obtained after channel coding to an extended access burst (EAB) structure, wherein the EAB structure occupies at least two continuous timeslots, the EAB structure comprises only one guard period (GP) part, the number of bits contained in the GP part is not less than the number of bits contained in a GP part of an access burst (AB) structure that occupies only one timeslot, the number of bits contained in an information bit part of the EAB structure is M, M is greater than 2N, and N is the largest number of bits contained in an information bit part of the AB structure that occupies only one timeslot; and sending the channel request message in a random access channel (RACH) according to the EAB structure.

Description

RACH coverage enhancement method and related equipment

This application claims priority to Chinese Patent Application No. 201410522751.X, entitled "RACH Coverage Enhancement Method and Related Equipment", filed on September 30, 2014, the entire contents of which are incorporated by reference. In this application.

Technical field

The present invention relates to the field of communications technologies, and in particular, to a method and related device for RACH coverage enhancement.

Background technique

Existing wireless cellular communication networks, such as Global System for Mobile communication (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), are mainly targeted at H2H (Human to Human), the main consideration of the wireless environment is outdoor or general indoor scenes.

The 3GPP (The 3rd Generation Partnership Project) standard has begun to consider supporting communication between M2M (Machine to Machine) through a wireless cellular network, that is, Machine Type Communication (Machine Type Communication, MTC). Since the terminal devices of some M2M applications, that is, the locations where the MTC devices are placed, are located in unmanned areas such as basements, tunnels, valleys, and forests, the signal coverage of these places is relatively poor. In order to make the devices located in these poor coverage areas communicate with the network side normally, it is necessary to improve the coverage performance of the terminals located in these areas.

The coverage performance is mainly related to the transmit power of the transmitter and the receiver sensitivity of the receiver. Further, the receiver sensitivity and thermal noise density, the receive noise figure, the interference margin, the channel bandwidth, and the receiver's demodulation threshold SINR (Signal to Interference plus) Noise Ratio, signal to interference plus noise ratio). The main design parameters are the channel bandwidth and the receiver's demodulation threshold SINR.

Coverage performance enhancements involve various channel types used throughout the communication process. A Random Access Channel (RACH) channel is a letter used by a terminal to initiate an access request to a network. Road, its coverage performance also needs to be enhanced.

Repeated delivery is a common method of improving coverage performance. By repeatedly transmitting the receiving end, the data received by multiple times can be combined and demodulated to reduce the value of the demodulation threshold SINR, thereby improving the MCL and achieving the purpose of improving the coverage performance. Coverage enhancement of the RACH channel can also be implemented using repeated transmissions.

The access burst (AB) format of the existing RACH channel in the GSM system is shown in FIG. 1 . The scheme of repeated transmission is transmitted multiple times according to the RACH channel information of the format. Considering the distance between the terminal and the base station side in the format, the GP (guard period) part is used to ensure that the signal sent by the terminal arrives at the base station side and does not cause interference to the terminals of other time slots. Considering the larger cell coverage (which can support 35 km of cell coverage in this structure), the guard interval portion occupies more bits, for example 68.25 bits. Each AB structure contains guard interval information when it is repeatedly transmitted. The repeated RACH transmission consumes a large amount of time resources because of the guard interval, which reduces the resource utilization. The less coded information bits result in higher demodulation threshold SINR and poor coverage performance of the effective information before the correct reception of the code.

Summary of the invention

The embodiment of the invention provides a method and related device for RACH coverage enhancement, so as to reduce waste of time resources, improve resource utilization, and improve coverage performance of RACH.

A first aspect of the present invention provides a method for RACH coverage enhancement, including:

Mapping the channel-encoded channel request message into an extended access burst EAB structure, the EAB structure occupies at least two consecutive time slots, the EAB structure includes only one guard interval GP part, and the GP The number of bits included in the part is not less than the number of bits included in the GP part of the access burst AB structure occupying only one slot, and the information bit part in the EAB structure contains M, M is greater than 2N, N is the maximum number of bits included in the information bit portion of the AB structure occupying only one slot; the channel request message is transmitted in the random access channel RACH according to the EAB structure.

With reference to the first aspect, in a first possible implementation manner, before the channel coding channel request message is mapped into the extended access burst EAB structure, the method further includes: performing channel request message less than 1/2 The channel coding of the code rate matches the number of bits obtained after encoding to the required number of bits to obtain a coded bit sequence with a bit number greater than 2N but not greater than M.

With reference to the first aspect or the first possible implementation manner of the first aspect, in the second possible implementation manner, the channel request message includes coverage level information or terminal identifier information.

With reference to the first aspect or the first or second possible implementation manner of the first aspect, in a third possible implementation manner, the EAB structure includes the following parts: a tail bit, a synchronization sequence, an information bit, and a guard interval. GP; wherein the number of bits included in the synchronization sequence portion is greater than or equal to the number of bits included in the synchronization sequence portion of the AB structure occupying only one slot.

A third possible implementation manner of the first aspect, in a fourth possible implementation, the number of bits included in the synchronization sequence part is a bit included in a synchronization sequence part of an AB structure occupying only one time slot 2 times the number.

With reference to the fourth possible implementation manner of the first aspect, in a fifth possible implementation, the synchronization sequence part is divided into two parts of equal length, which are respectively used to carry two identical synchronization sequences, each The synchronization sequence is the same as the synchronization sequence in the AB structure.

A second aspect of the present invention provides another method for RACH coverage enhancement, comprising:

Receiving, in the random access channel RACH, a channel request message sent according to the extended access burst EAB structure, the EAB structure occupies at least two consecutive time slots, and the EAB structure includes only one guard interval GP part, and The number of bits included in the GP part is not less than the number of bits included in the GP part of the access burst AB structure occupying only one slot, and the information bit part in the EAB structure contains the number of bits M, M. More than 2N, N is the maximum number of bits included in the information bit portion of the AB structure occupying only one slot; the channel request message is extracted from the EAB structure.

A third aspect of the present invention provides a terminal device, including:

a mapping module, configured to map a channel-encoded channel request message into an extended access burst EAB structure, where the EAB structure occupies at least two consecutive time slots, and the EAB structure includes only one guard interval GP part And the number of bits included in the GP part is not less than the number of bits included in the GP part of the access burst AB structure occupying only one slot, and the information bit part in the EAB structure includes the number of bits M M is greater than 2N, where N is the maximum number of bits included in the information bit portion of the AB structure occupying only one slot; and the transmitting module is configured to send the channel request message in the random access channel RACH according to the EAB structure.

With reference to the third aspect, in a first possible implementation manner, the terminal device further includes: coding a module, configured to perform channel coding of a channel request message with a rate lower than 1/2 code rate, and match the number of bits obtained by coding to a required number of bits to obtain a coded bit sequence with a bit number greater than 2N but not greater than M .

A fourth aspect of the present invention provides a network side device, including:

a receiving module, configured to receive, in a random access channel RACH, a channel request message sent according to an extended access burst EAB structure, where the EAB structure occupies at least two consecutive time slots, and the EAB structure includes only one protection Interval GP part, and the number of bits included in the GP part is not less than the number of bits included in the GP part of the access burst AB structure occupying only one time slot, and the information bit part of the EAB structure contains bits The number is M, M is greater than 2N, and N is the maximum number of bits of the information bit portion in the AB structure occupying only one time slot; and an extracting module is configured to extract the channel request message from the EAB structure.

It can be seen that the embodiment of the present invention combines at least two consecutive time slots into one extended access burst EAB in the RACH channel, and the EAB structure only includes one guard interval GP part, and the number of bits included in the GP part Not less than the number of bits included in the GP part of the access burst AB structure occupying only one slot. The information bit part of the EAB structure contains M, M is greater than 2N, and N is only one slot. The number of bits that the information bit portion in the AB structure contains at most, the prior art that uses one guard interval for each time slot in the simple repetition scheme, substantially reduces the number of bits of the guard interval portion, and increases the bits of the information bit portion. The number has thus achieved the following beneficial effects:

On the one hand, in the case that the effective information of the bearer, such as the number of bits of the channel request message, is unchanged, since the information bit portion of the EAB is increased, the coding redundancy of the effective information can be improved, the mediation threshold is lowered, and the RACH is further improved. Coverage performance

On the other hand, as the information bit portion increases, the EAB can carry more effective information, thereby improving the utilization of physical resources in the RACH;

In summary, the technical solution of the present invention reduces the time resource occupied by the guard interval portion by combining the time slots, and improves the time resource occupied by the information bit portion, thereby improving the time resource occupied by the information bit portion. RACH coverage enhancement can be implemented, which can improve the utilization of physical resources.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments and the prior art description will be briefly described below. Obviously, the drawings in the following description are only some implementations of the present invention. For example, other drawings may be obtained from those skilled in the art without any inventive effort.

1 is a structural diagram of an access burst (AB) of a RACH channel in the prior art;

2 is a flowchart of a method for RACH coverage enhancement according to an embodiment of the present invention;

3a-3c are structural diagrams of several extended access bursts (EABs) in an embodiment of the present invention;

4a-4c are flow diagrams of several channel encodings in some embodiments of the invention;

Figure 5 is a flow chart of channel coding in other embodiments of the present invention;

6 is a flowchart of a method for RACH coverage enhancement according to another embodiment of the present invention;

FIG. 7 is a schematic diagram of a terminal device according to an embodiment of the present disclosure;

FIG. 7b is a schematic diagram of another terminal device according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a network side device according to an embodiment of the present disclosure;

FIG. 9 is a schematic diagram of a terminal device according to another embodiment of the present invention;

FIG. 10 is a schematic diagram of a network side device according to another embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is an embodiment of the invention, but not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of the present invention.

The detailed description will be respectively made below through specific embodiments.

Embodiment 1

Referring to FIG. 2, an embodiment of the present invention provides a method for enhancing RACH coverage, which may include:

110. Mapping the channel coded channel request message to the extended access burst EAB structure;

120. Send a channel request message in a random access channel (RACH) according to an EAB structure;

The EAB structure occupies at least two consecutive time slots, the EAB structure includes only one Guard period (GP) part, and the GP part includes no less than one bit. The number of bits included in the GP part of the access burst (AB) structure of the slot, the information bit part of the EAB structure contains the number of bits M, M is greater than 2N, and N is an AB structure occupying only one time slot. The number of bits that the information bit portion contains at most.

It can be seen that the embodiment of the present invention adopts an extended access burst EAB structure design on the RACH channel, and uses a prior art with a guard interval for each time slot, thereby substantially reducing the number of bits in the guard interval portion and increasing The number of bits in the information bit portion achieves the following beneficial effects:

On the one hand, in the case that the effective information of the bearer, such as the number of bits of the channel request message, is unchanged, since the information bit portion of the encoded information in the EAB is increased, the coding redundancy of the effective information can be improved, the mediation threshold is lowered, and the median threshold is further improved. RACH coverage performance;

On the other hand, as the information bit portion increases, the EAB can carry more valid information, thereby improving the utilization of time resources in the RACH;

The technical solutions of the embodiments of the present invention are further described in detail below.

First, the resource structure of the RACH in the embodiment of the present invention will be described.

RACH is an uplink transmission channel. For example, in the GSM system, when a terminal device such as a mobile station (MS) needs to establish communication with the network, it needs to send a channel request (CHANNEL REQUEST) to the network through the RACH to apply for a data channel, and the network side device, for example, the base station. The system (Base Station Subsystem, BSS), after receiving the channel request, allocates a data channel to the terminal device according to the channel request.

As shown in FIG. 1, it is the format of an access burst (AB) in the RACH channel of the existing GSM system. An AB occupies one time slot and contains 156.25 bits. An AB consists of the following parts:

Extendded tail bits occupying 8 bits to indicate the start of AB;

Synchronization sequence (Synch. Sequence bits), occupying 41 bits for channel estimation;

Information bits (encrypted bits), occupying 36 bits, for carrying valid information, such as channel request messages;

Tail bits occupying 3 bits to indicate the end of AB;

The Extended guard period, which occupies 68.25 bits, is used as the interval between ABs.

In the prior art, repeated transmission is used to enhance the coverage of the RACH channel, that is, two consecutive ABs transmit exactly the same content, so that two information bit portions can be used to carry valid information in the time resources of the two slots. 72 bits.

The embodiment of the present invention is preferably used in an M2M scenario. The terminal device in the M2M scenario is a device of the M2M device type. Considering that the M2M device is mostly used for static or low-speed moving scenarios, there is no obvious position change in a short time. Two ABs use two guard intervals when sending repeatedly, which wastes physical resources. For the purpose of improving the utilization of physical resources and further enhancing the coverage, in the embodiment of the present invention, at least two consecutive time slots are combined into one extended access burst (EAB).

Please refer to FIG. 3a - 3c, which are structural diagrams of an EAB in some embodiments of the present invention, in which two resources of a slot are combined into one EAB, and one EAB occupies two slots, including 312.5 bits. The following may be included: a tail bit, a synchronization sequence, an information bit, and a guard interval; wherein the tail bit portion specifically includes a first tail bit and a second tail bit.

The first tail bit, that is, the extended tail bits, should occupy no less than the number of bits included in the extended tail bit portion of the AB structure, for example, 8 to 16 bits can be used for clear The initial or end state of the equalization algorithm. Take 3bits as an example in Figure 3a.

The synchronization sequence (Synch. Sequence bits) may occupy more than or equal to the number of bits included in the synchronization sequence part of the AB structure, for example, may occupy 41 to 82 bits for channel estimation. The synchronization sequence in the EAB can be redesigned through its autocorrelation performance at different bit lengths. Another alternative way to simplify the design is that the synchronization sequence part of the EAB structure can occupy twice the length of the synchronization sequence in the AB structure, that is, 82 bits, divided into two parts, each part 41 bits, and two Ministry The sub-bearings carry exactly the same content, that is, equivalent to repeating the transmission of the synchronization sequence in the AB structure occupying only one slot, in order to improve the performance of the channel estimation in the case of low signal-to-noise ratio. Take the example of occupying 82 bits in Figure 3a. In the EAB structure shown in Figure 3a, the synchronization sequence is located between the first tail bit and the information bit.

It should be noted that in other embodiments, as shown in FIG. 3b, the synchronization sequence may also be located in the middle of the information bits. For more information bits, the synchronization sequence located in the middle facilitates the demodulation of both sides of the data using more accurate channel estimation results, and improves the demodulation performance of the data.

Information bits (encrypted bits), which can occupy more than twice the number of bits contained in the information bit portion of the AB structure, for example, can occupy 73-192 bits for carrying valid information, such as Channel request message. Take the example of occupying 150 bits in Figure 3a. Compared with the prior art, the AB structure occupies only one slot, and the information bit portions of the two AB structures occupy 2N=72 bits in the same two slot resources (in the AB structure occupying one slot) The information bit length is N=36), and in the embodiment of the present invention, the information bit portion of an EAB structure can occupy 150 bits, which is more than doubled.

The second tail bit, that is, the Tail bits, should occupy no less than the number of bits included in the tail bit portion of the AB structure. For example, it can occupy 3 to 6 bits for clearing the initial or end of the equalization algorithm. status. Take 3bits as an example in Figure 3a.

The number of bits occupied by the protection interval (GP) should not be less than the number of bits included in the protection interval part of the AB structure, that is, occupy at least 68.25. For example, as shown in FIG. 3a, it can occupy 68.5 bits. To protect the interference caused by the time synchronization caused by the different distance between each terminal device and the network device. The number of bits occupied by the GP portion is not less than the number of bits included in the GP portion of the AB structure, and the coverage of the base station (for example, maintaining the coverage radius of not less than 35 Km) is not reduced. In order to increase the number of bits occupied by the information bit portion as much as possible, in the embodiment of the present invention, it is preferable to control the number of bits of the GP portion in the EAB to be not more than a preset upper limit value, wherein the content of the guard interval portion included in the AB structure may be greater than The smallest integer of the number of bits is used as a preset upper limit value, for example, the number of bits of the GP portion in the EAB is controlled to be no more than 69. Of course, the number of bits occupied by the guard interval can also be increased or decreased in consideration of the changing requirements of the actual coverage.

Please refer to FIG. 3c, which is a structural diagram of an EAB in still another embodiment of the present invention. among them,

The first tail bit portion can occupy 16 bits and is divided into two parts, each part 8 bits, to repeat The same 8 bits of tail bit data are transmitted, and the first tail bit of each part of 8 bits can be the same as the synchronization sequence in the AB structure occupying only one time slot.

The second tail bit portion can occupy 6 bits and is divided into two parts, each part of which is 3 bits, to repeatedly transmit the same 3 bits of tail bit data, and the second tail bit of each part of 3 bits can be combined with the AB structure occupying only one time slot. The synchronization sequence in is the same.

The synchronization sequence part can occupy 82 bits and is divided into two parts, each part is 41 bits, to repeatedly transmit the same 41-bit synchronization sequence data, and the synchronization sequence of each part of 41 bits can be synchronized with the synchronization sequence of the AB structure occupying only one time slot. the same.

The guard interval portion can occupy 68.5 bits.

The information bit portion can occupy 140 bits.

It should be understood that the above-mentioned FIGS. 3a-3c are only partial implementations of the EAB structure in the present invention. In other embodiments, there may be other more ways of the EAB structure.

It can be seen that, in the EAB structure designed by the embodiment of the present invention, only one guard interval is used, and the number of bits included in the guard interval portion is not less than the number of bits included in the guard interval portion of the AB structure occupying only one slot. Other information parts, such as the Synch. Sequence bits section, can increase the number of bits in consideration of improving the performance of channel estimation in the case of low SNR. For the simplified design, the synchronization sequence in the AB structure occupying one slot can be used. Repeated delivery. The tail bit portion has little effect on the demodulation performance of the information, so the number of bits can be increased or the number of bits can be increased. With the above design, the information bit portion for carrying valid information can be greater than twice the number of information bits in the AB structure 2N=72.

In the prior art, the information bit portion of a time slot resource is 36 bits, and the information bit portion of the two time slot resources occupies 36*2=72 bits in a total of two times. In the embodiment of the present invention, The information bit portion carrying the payload information can be increased to about 150 bits, so that the newly designed AB can carry more than twice as much effective information as the prior art. Therefore, on the one hand, in the embodiment of the present invention, the coding redundancy of the effective information can be greatly improved, the demodulation threshold is reduced, and the coverage performance is improved. On the other hand, in the case of the same demodulation threshold, the channel request message can be placed in the channel request message. More information needs to be carried.

The resource structure of the RACH in the embodiment of the present invention has been described above. The implementation process of the RACH in the embodiment of the present invention, including the encoding process, is described in detail below.

The terminal device is a mobile station (Mobile Station, MS) of the GSM system, and the network side device is a base station subsystem (BSS) of the GSM system as an example. When the MS is powered on, it will detect nearby broadcast channel signals, perform cell selection, and select a cell to camp on. Then, the MS sends a channel request message to the BSS through the RACH channel to implement network access. In other scenarios, such as cell handover or cell reselection, the mobile station also sends a channel request message to the BSS through the RACH channel to implement network access. Herein, the timing at which the terminal device sends a channel request to the network side device is not limited.

The terminal device, for example, the mobile station, sends a channel request message to the network side device, such as the BSS, through the RACH channel, which can be understood as: mapping the channel coded channel request message into the EAB structure, and transmitting the channel in the RACH channel according to the EAB structure. Request message. Specifically, the method may be: first, the terminal device performs channel coding on the channel request message, and generates a coded bit sequence, for example, encoding the channel request message by using a convolutional coding or a repetition coding manner that is lower than a 1/2 code rate, and encoding the channel request message. The obtained number of bits is matched to the required number of bits to obtain a coded bit sequence with a bit number greater than 2N but not greater than M; then, the coded bit sequence is mapped to the information bit portion of the EAB structure, and the RACH channel is according to the EAB structure. Send to the network side device.

In the prior art, the RACH needs to carry valid information, that is, a channel request (CHANNEL REQUEST) message, and generally has 8 bits and 11 bits. Generally, the channel request message includes at least an access reason value (ESTABLISHMENT CAUSE) and a random reference value (ESTABLISHMENT CAUSE). Taking an 8-bit channel request message as an example, the 8 bits may include: a 3-6 bit access cause value, and a 5-2 bit random reference value. The information of the PACKET CHANNEL REQUEST, in addition to the access reason value and the random reference value, may also include other information that needs to be carried, which can be obtained by referring to the relevant protocol, and is not described herein again. When a channel request needs to be sent, the 8-bit and 11-bit channel request messages are channel-encoded, resulting in tens of bits of the encoded bit sequence, mapped into the AB structure.

The main purpose of channel coding is to improve the quality of signal transmission. In general, the higher the coding redundancy, the more the number of bits of the encoded bit sequence, the lower the demodulation threshold and the stronger the channel coverage performance. In the AB structure occupying one slot in the prior art, the channel-coded post-coded bit sequence can only contain at most 36 bits. In the EAB structure occupying two slots in the present invention, the information bit portion can include 150 Bits (as shown in Figure 3a), taking into account the information bits occupied by the two repeated transmissions are 72 bits, the coded post-coded bit sequence designed by the present invention can achieve more than twice the number of information bits in the repeated transmission mode, and thus the RACH channel coverage in the present invention can be greatly enhanced. In the embodiment of the present invention, more information about the bearer needs to be placed in the EAB structure, for example, in addition to the access cause value and the random reference value, and may include information such as the coverage level or the terminal identifier. At least one of them.

During the encoding process, some check protection information is generally added for network side equipment such as BSS error correction; and some source information, such as Base Station Identity Code (BSIC), is also added for network side equipment. For example, BSS identifies the information that is sent to you. The BSIC can be understood as the identification information of the network side device.

Please refer to FIG. 4a, which is a flowchart of channel coding in some embodiments of the present invention, including the following steps:

401. Determine information bits of the channel request message, and obtain a BSIC.

The channel request message is exemplified by including 11 bits, and is represented by d0, d1, d2, ..., d10, respectively. The BSIC generally includes 6 bits, which are denoted by b0, b1, b2, ..., b5, respectively. A network side device such as a BSS generally carries a BSIC in a synchronization channel (SCH) and broadcasts it to a terminal device such as a mobile station. A terminal device, such as a mobile station, may obtain a BSIC by receiving a cell broadcast channel such as SCH during cell selection.

402. Generate a plurality of bits of parity protection information according to the information bits of the channel request message.

The verification protection information may be calculated according to the information bits of the channel request message by using a commonly used algorithm such as a Cyclic Redundancy Check (CRC) algorithm. In Fig. 4, g(D) = D6 + D5 + D3 + D2 + D + 1 is a generator polynomial of the check protection information. The 6 bits of parity protection information can be generated by the information bit of the 11-bit channel request message and the generator polynomial g(D).

403. Perform an exclusive OR operation on the check protection information and the BSIC.

The X-bit check protection information and the 6-bit BSIC are XORed to obtain 6 bits, which can be represented by C0, C1, C2, ..., C5, respectively. The 11 bits included in the channel request message, plus the 6 bits obtained by the exclusive OR operation, have a total of 17 bits of information, and channel coding is required.

404. Perform channel coding with a code rate less than 1/2, and generate a coded bit sequence.

Optionally, a common channel coding method, convolutional coding, is taken as an example.

First, multiple bits of the information bits of the channel request message can be XORed, and A plurality of padding bits are sorted to form a bit sequence. For example, the 11 bits of the channel request message, the 6 bits obtained by the exclusive OR operation of 403, and the padding bits of 4 bits are sequentially sorted to form a 21-bit bit sequence. The purpose of the padding bits is to give an end state value for subsequent convolutional coding. The tail bits (also referred to as tail bits) are generally ranked at the last bit of the bit sequence and may all be zero. It should be emphasized that the addition of the tail bit is not a necessary step here, and the addition of the tail bit can improve the decoding performance to a certain extent, but also increases the overhead of transmitting information. In the present invention, only convolutional coding in which tail bits need to be added is taken as an example. A convolutional code that requires the addition of 0 bits is called a return-to-zero convolutional code; a convolutional code that does not require the addition of a tail bit is called a tail-biting convolutional code.

Then, channel coding is performed at a code rate lower than 1/2. The coding rate (referred to as the code rate) may be different depending on the channel protection requirements. The lower the code rate, the more redundant bits, the better the parity performance. In the embodiment of the present invention, convolutional coding can be performed with a code rate of less than 1/2.

In Fig. 4a, for a 21-bit bit sequence, convolutional coding can be performed at a code rate of 1/7, and a 148-bit redundant bit sequence can be obtained, which can be represented by c0, c1, c2, ..., c146, respectively. It should be noted that only the code rate proposal is proposed here, and other convolutional coding features are not limited, such as recursive convolutional codes or non-recursive convolutional codes; or truncated convolutional codes, zeroed convolutional codes or bites. The tail convolutional code can be used as an implementation method of the present invention. Taking the EAB structure shown in FIG. 3c as an example, the information bit portion includes only 140 bits, and the 148-bit redundant bit sequence can be punctured to remove 7 bits and matched to 140 bits, respectively, using e0, e1, respectively. E2...e139 represent as the encoded bit sequence. The specific position of the punching is not limited in the present invention and can be selected by evaluation of performance.

For example, in FIG. 4b, for a 21-bit bit sequence, convolutional coding can also be performed at a code rate of 1/8, and a 168-bit redundant bit sequence can be obtained, which can be represented by c0, c1, c2, ..., c167, respectively. Taking the EAB structure shown in FIGS. 3a and 3b as an example, the information bit portion includes 150 bits. Therefore, 18 bits can be removed by puncturing to obtain 150 bits of information, which are represented by e0, e1, e2, ..., e149, respectively. , as the encoded bit sequence.

It should be noted that, in the embodiment of the present invention, channel coding is not limited to using a convolutional coding method, and other coding modes may also be used. Another alternative channel coding method is repetitive coding.

Referring to FIG. 4c, the channel coding flow chart taking the repeated coding mode as an example is different from the above convolutional coding in that after the exclusive OR operation, the obtained 17-bit information is repeated 9 times. 153 bits. Taking the EAB structure shown in Figs. 3a and 3b as an example, the information bit portion includes 150 bits, and therefore, the latter 3 bits are removed to obtain 150 bits of information as the encoded bit sequence.

The channel coding process of the technical solution of the present invention will be described above by taking the convolutional coding and the repetition coding as an example. However, it should be understood that in practical applications, other coding methods may be used for channel coding, and are not limited to using convolutional coding or repeated coding.

To facilitate a better understanding of the channel coding process in the embodiment of the present invention, another embodiment is described below as an example.

Please refer to FIG. 5, which is a flowchart of channel coding in other embodiments of the present invention, including the following steps:

501. Determine information bits of the channel request message, and obtain a BSIC.

In the embodiment of the present invention, since the information bit portion of the EAB structure contains more bits than the information bit portion of the AB structure, more information to be carried can be placed in the EAB structure, for example, except for access reasons. The value and the random reference value may further include one or more of the coverage level or the terminal identifier, and the network side uses the coverage level information to effectively allocate the resource usage of the terminal in the coverage enhanced scenario, or In the period of entry, a clear distinction between terminal identification is conducive to the resolution of competition conflicts. In this embodiment, the channel request message includes 40 bits as an example, and is represented by d0, d1, d2, ..., d39, respectively. The BSIC generally includes 6 bits, which are denoted by b0, b1, b2, ..., b5, respectively.

502. Generate multiple bits of parity protection information according to information bits of the channel request message.

In Fig. 5, g(D) = D8 + D6 + D3 + 1 is a generator polynomial of the check protection information. The information protection bits of the 40-bit channel request message and the generator polynomial g(D) can be generated to generate 8 bits of parity protection information. It can be represented by p0, p1, p2, ..., p7, respectively.

503. Perform an exclusive OR operation on the check protection information and the BSIC.

The first 6 bits of the 8-bits check protection information and the 6-bit BSIC are XORed, and then the 2 bits of the check bits are added to obtain 8 bits, which can be represented by C0, C1, C2, ..., C7, respectively.

504. Perform channel coding with a code rate less than 1/2, and generate a coded bit sequence.

Take the convolutional coding method that requires the addition of the tail bits as an example. First, the 40 bits of the channel request message, the 8-bits obtained by the XOR operation, and the padding bits of 4 bits can be sequentially sorted to form a 52-bit bit sequence. Then, for a 52-bit bit sequence, convolutional coding can be performed at a code rate of 1/3, and a redundant bit sequence of 156 bits can be obtained, which can be represented by c0, c1, c2, ..., c155, respectively. Finally, The 156-bit redundant bit sequence is punctured to remove 16 bits and matched to 140 bits, which are represented by e0, e1, e2, ..., e139, respectively, as the encoded bit sequence.

After the channel coding is completed, the information mapping and transmission process is entered to implement network access.

The terminal device, for example, the mobile station, may map the encoded bit sequence obtained by channel coding to the information bit portion of the EAB structure, and transmit it to the network side device such as the BSS in the RACH channel.

After receiving the channel request message, the network side device, such as the BSS, may extract information from the information bit portion of the EAB structure and demodulate the information to obtain a channel request message; and then allocate a data channel to the terminal device, such as the mobile station, according to the channel request message, and allocate The information of the data channel is carried in the assignment message and sent to the terminal device. For example, the GSM system can be carried in the immediate assignment command and sent to the terminal device, such as the MS, through an Access Grant Channel (AGCH).

After the terminal device, for example, the assignment message received by the mobile station, the information of the data channel allocated for the mobile station included in the assignment message can be obtained. Further, the network access can be realized through the steps of service request, authentication, and the like. The specific access process can refer to the definition of the related protocol, and details are not described in detail herein.

It should be noted that the information of the data channel to be allocated is not limited to being carried in the immediate assignment command of the AGCH channel, and may be carried in other assignment messages, which is not limited herein.

In summary, in the embodiment of the present invention, considering that the M2M device is mostly used for static or low-speed moving scenarios, there is no obvious position change in a short time, so the EACH structure is adopted in the RACH channel, and at least two consecutive The combination of time slots into one EAB, using a guard interval with respect to each time slot, substantially reduces the number of bits in the guard interval portion and increases the number of bits in the information bit portion, thereby achieving the following beneficial effects:

It can be seen that, compared with the prior art in which each guard slot uses one guard interval, the technical solution of the present invention reduces the time resource occupied by the guard interval portion by combining the time slots, thereby improving the time resource occupied by the information bit portion, thereby Realizing RACH coverage enhancement can improve the utilization of physical resources.

Embodiment 2

Referring to FIG. 6, an embodiment of the present invention further provides another method for RACH coverage enhancement.

Different from the first embodiment, the terminal device is the execution subject. In this embodiment, the network side device is used as the execution subject. Methods can include:

610. Receive, in a random access channel RACH, a channel request message that is sent according to an extended access burst EAB structure.

The EAB structure occupies at least two consecutive time slots, the EAB structure includes only one guard interval GP part, and the GP part contains not less than the access burst AB occupying only one time slot. The number of bits included in the GP part of the structure, the information bit part of the EAB structure contains M, M is greater than 2N, and N is the maximum number of bits of the information bit part of the AB structure occupying only one time slot. ;

620. Extract the channel request message from the EAB structure.

Optionally, the channel request message includes coverage level information or terminal identifier information.

Optionally, the EAB structure includes the following parts: a tail bit, a synchronization sequence, an information bit, and a guard interval GP. The synchronization sequence part includes a number of bits greater than a synchronization sequence part of the AB structure occupying only one time slot. The number of bits included.

Optionally, the number of bits included in the synchronization sequence part is twice the number of bits included in the synchronization sequence part of the AB structure occupying only one time slot.

For a more detailed description of the method of the present embodiment, please refer to the content described in the first embodiment.

In summary, in the embodiment of the present invention, considering that the M2M device is mostly used for static or low-speed moving scenarios, there is no obvious position change in a short time, so the EACH structure is adopted in the RACH channel, and at least two consecutive The combination of time slots into one EAB, using a guard interval for each time slot, substantially reduces the number of bits in the guard interval and increases the number of bits in the information bit portion, thereby achieving the following beneficial effects:

On the other hand, as the information bit portion increases, EAB can carry more valid information from And improve the utilization of time resources in RACH;

In order to better implement the above solution of the embodiments of the present invention, related devices for cooperating to implement the above solutions are also provided below.

Embodiment 3

Referring to FIG. 7a, an embodiment of the present invention provides a terminal device, which may include:

The mapping module 710 is configured to map the channel coded channel request message into the extended access burst EAB structure;

The sending module 720 is configured to send the channel request message in a random access channel (RACH) according to the EAB structure;

The EAB structure occupies at least two consecutive time slots, the EAB structure includes only one guard interval GP part, and the GP part contains not less than the access burst occupying only one time slot. The number of bits included in the GP part of the AB structure, the information bit part of the EAB structure contains M, M is greater than 2N, and N is the information bit part of the AB structure occupying only one time slot. The number of bits.

Referring to FIG. 7b, in some embodiments of the present invention, the terminal device may further include:

The coding module 730 is configured to perform channel coding on the channel request message with a rate lower than 1/2 code rate, and match the number of bits obtained after the coding to the required number of bits to obtain a coded number of bits greater than 2N but not greater than M. Bit sequence.

The above embodiment discloses a terminal device, such as a mobile station in the GSM system, and the mobile station may specifically be an M2M device. For a more detailed description of the terminal device of this embodiment, please refer to the content described in the first embodiment.

It is to be understood that the functions of the various functional modules of the terminal device in the embodiments of the present invention may be specifically implemented according to the method in the foregoing method embodiments. For the specific implementation process, refer to the related description in the foregoing method embodiments, and details are not described herein again.

In summary, in the embodiment of the present invention, considering that the M2M device is mostly used for static or low-speed moving scenarios, there is no obvious position change in a short time, so the EACH structure is adopted in the RACH channel, and at least two consecutive The time slots are combined into one EAB, and the prior art using a guard interval with respect to each time slot substantially reduces the number of bits of the guard interval and increases the number of bits of the information bit portion of the AB, thereby achieving the following beneficial effects. :

Embodiment 4

Referring to FIG. 8 , an embodiment of the present invention provides a network side device, which may include:

The receiving module 810 is configured to receive, in the random access channel RACH, a channel request message that is sent according to the extended access burst EAB structure;

The extracting module 820 is configured to extract the channel request message from the EAB structure;

In the above, the embodiment discloses a network side device, such as a base station subsystem in the GSM system. For a more detailed description of the network side device of this embodiment, please refer to the contents described in the first embodiment and the second embodiment.

It can be understood that the functions of the respective functional modules of the network side device according to the embodiment of the present invention may be based on the foregoing. The method in the method embodiment is specifically implemented. For the specific implementation process, reference may be made to the related description in the foregoing method embodiments, and details are not described herein again.

The embodiment of the invention further provides a computer storage medium, wherein the computer storage medium can store a program, and the program includes some or all of the steps of the RACH coverage enhancement method described in the first embodiment.

The embodiment of the present invention further provides a computer storage medium, where the computer storage medium can store a program, and the program includes some or all of the steps of the RACH coverage enhancement method described in the second embodiment.

Referring to FIG. 9, an embodiment of the present invention further provides a terminal device 200, which may include:

Receiver 210, transmitter 220, memory 230, and processor 240. In some embodiments of the present invention, the receiver 210, the transmitter 220, the memory 230, and the processor 240 may be connected by a bus or other means, wherein the connection through the bus 250 is exemplified in FIG.

When the terminal device 200 is running, the processor 240 may control the flow of the method for the transmitter 220 to perform the RACH coverage enhancement described in the first embodiment of the method. Wherein the processor 240 encodes the channel The channel request message is mapped into the extended access burst EAB structure; the transmitter 220 transmits the channel request message in the random access channel RACH according to the EAB structure.

It can be seen from the above that in some feasible embodiments of the present invention, considering that the M2M device is mostly used for static or low-speed moving scenarios, there is no obvious position change in a short time, and thus the EACH structure design is adopted in the RACH channel. Combining at least two consecutive time slots into one EAB, using a prior art with a guard interval for each time slot, substantially reducing the number of bits of the guard interval, increasing the number of bits of the information bit portion of the AB, thereby obtaining The following benefits:

Referring to FIG. 10, an embodiment of the present invention further provides a network side device 300, which may include:

Receiver 310, transmitter 320, memory 330, and processor 340. In some embodiments of the present invention, the receiver 310, the transmitter 320, the memory 330, and the processor 340 may be connected by a bus or other means, wherein the connection by the bus 350 is exemplified in FIG.

When the network side device 300 is running, the processor 340 can control the method flow that the receiver 310 performs the RACH coverage enhancement described in the second embodiment. The receiver 310 receives the channel request message sent according to the extended access burst EAB structure in the random access channel RACH; the processor 340 extracts the channel request message from the EAB structure.

In the above embodiments, the descriptions of the various embodiments are different, and the parts that are not described in detail in a certain embodiment can be referred to the related description of other embodiments.

It should be noted that, for the foregoing method embodiments, for the sake of brevity, they are all described as a series of action combinations, but those skilled in the art should understand that the present invention is not limited by the described action sequence, because In accordance with the present invention, certain steps may be performed in other sequences or concurrently. In addition, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

A person skilled in the art may understand that all or part of the various steps of the foregoing embodiments may be performed by a program to instruct related hardware. The program may be stored in a computer readable storage medium, and the storage medium may include: ROM, RAM, disk or CD.

The method and related device for enhancing the RACH coverage provided by the embodiment of the present invention are described in detail. The principles and implementation manners of the present invention are described in the following. The description of the foregoing embodiment is only used to help understand the present invention. The method of the invention and its core idea; at the same time, for the person of ordinary skill in the art, according to the idea of the present invention, there are some changes in the specific embodiment and the scope of application. In summary, the content of the specification should not be understood. To limit the invention.

Claims

A method for RACH coverage enhancement of a random access channel, comprising:

Mapping the channel-encoded channel request message into an extended access burst EAB structure, the EAB structure occupies at least two consecutive time slots, the EAB structure includes only one guard interval GP part, and the GP The number of bits included in the part is not less than the number of bits included in the GP part of the access burst AB structure occupying only one slot, and the information bit part in the EAB structure contains M, M is greater than 2N, N is the maximum number of bits included in the information bit portion of the AB structure occupying only one slot;

The channel request message is sent in a random access channel RACH according to the EAB structure.
The method according to claim 1, wherein the mapping the channel-encoded channel request message to the extended access burst EAB structure further comprises:

The channel request message is subjected to channel coding lower than 1/2 code rate, and the number of bits obtained after coding is matched to the required number of bits to obtain a coded bit sequence whose bit number is greater than 2N but not larger than M.
The method of claim 1 wherein

The channel request message includes coverage level information or terminal identification information.
A method according to any one of claims 1-3, characterized in that

The EAB structure includes the following parts: a tail bit, a synchronization sequence, an information bit, and a guard interval GP; wherein the synchronization sequence portion includes a number of bits greater than or equal to a synchronization sequence portion of the AB structure occupying only one time slot. The number of bits.
The method of claim 4 wherein:

The number of bits included in the synchronization sequence portion is twice the number of bits included in the synchronization sequence portion of the AB structure occupying only one slot.
The method of claim 5 wherein:

The synchronization sequence portion is divided into two parts of equal length for respectively carrying two identical synchronization sequences, each synchronization sequence being the same as the synchronization sequence in the AB structure.
A method for RACH coverage enhancement of a random access channel, comprising:

Receiving, in the random access channel RACH, a channel request message sent according to the extended access burst EAB structure, the EAB structure occupies at least two consecutive time slots, and the EAB structure only includes one The guard interval GP part, and the number of bits included in the GP part is not less than the number of bits included in the GP part of the access burst AB structure occupying only one time slot, and the information bit part in the EAB structure includes The number of bits is M, M is greater than 2N, and N is the maximum number of bits included in the information bit portion of the AB structure occupying only one slot;

The channel request message is extracted from the EAB structure.
A terminal device, comprising:

a mapping module, configured to map a channel-encoded channel request message into an extended access burst EAB structure, where the EAB structure occupies at least two consecutive time slots, and the EAB structure includes only one guard interval GP part And the number of bits included in the GP part is not less than the number of bits included in the GP part of the access burst AB structure occupying only one slot, and the information bit part in the EAB structure includes the number of bits M , M is greater than 2N, where N is the maximum number of bits included in the information bit portion of the AB structure occupying only one slot;

And a sending module, configured to send the channel request message in a random access channel (RACH) according to the EAB structure.
The terminal device according to claim 8, further comprising:

The coding module is configured to perform channel coding on the channel request message with a rate lower than 1/2 code rate, and match the number of bits obtained after the coding to the required number of bits to obtain a coded bit with a bit number greater than 2N but not greater than M. sequence.
A network side device, comprising:

a receiving module, configured to receive, in a random access channel RACH, a channel request message sent according to an extended access burst EAB structure, where the EAB structure occupies at least two consecutive time slots, and the EAB structure includes only one protection Interval GP part, and the number of bits included in the GP part is not less than the number of bits included in the GP part of the access burst AB structure occupying only one time slot, and the information bit part of the EAB structure contains bits The number is M, M is greater than 2N, and N is the maximum number of bits included in the information bit portion of the AB structure occupying only one time slot;

And an extracting module, configured to extract the channel request message from the EAB structure.