Patent Description:
A random access procedure is a basic function in LTE (long term evolution system, Long Term Evaluation). Only after a user equipment is synchronized with an uplink of a system through the random access procedure can the user equipment be scheduled by the system to perform uplink transmission (for example, transmission of uplink data or transmission of uplink control information). Random access in the LTE is classified into two forms, that is, contention-based random access (that is, a network side does not assign a dedicated random access sequence to the user equipment) and non-contention random access.

As shown in <FIG>, a contention-based random access procedure includes the following four steps.

First step (MSG1): A user equipment sends random access sequences (Random access preamble) selected by the user equipment to a network side over a PRACH (Physical Random Access Channel, physical random access channel) selected by the user equipment. The random access sequences are divided by the network side into a group A and a group B, and according to the size of a message required to be sent and the loss of a current downlink path of the user equipment, the user equipment decides whether to select and send a random access sequence in the group A or select and send a random access sequence in the group B.

Second step (MSG2): The network side sends a random access response (Random access response) to the user equipment. The random access response includes an index number of a detected preamble sequence, time adjustment information used for uplink synchronization, an initial uplink resource assignment (used for sending a subsequent MSG3) and a temporary C-RNTI (Cell-RNTI, serving cell-radio network temporary identifier, where it is decided whether the temporary C-RNTI is to be converted into a permanent C-RNTI in an MSG4). The user equipment needs to receive the corresponding MSG2 (the random access response) through interception on a PDCCH (Physical Downlink Control Channel, physical downlink control channel) scrambled by an RA-RNTI (Random Access-RNTI, random access-radio network temporary identifier).

Though the user equipment intercepts the MSG2, because the MSG1 sent by the user equipment is randomly selected from public resources, it is possible that different user equipments send the same MSG1 (random access sequence) over a PRACH resource of the same time and frequency, so that the user equipment needs to solve this random access contention through subsequent MSG3 and MSG4 (a contention resolution message).

Third step (MSG3): The user equipment sends the MSG3 to the network side. The content of the MSG3 is not limited. The MSG3 sometimes may carry an RRC (Radio Resource Control, radio resource control protocol) connection request and sometimes may carry some control information or service data packets, and sometimes, to distinguish different user equipments, the MSG3 may also carry a specific ID of the user equipment. The MSG3 is a message transmitted over a PUSCH (Physical Uplink Shared Channel, physical uplink shared channel).

Fourth step (MSG4): The network side sends, to the user equipment, a contention resolution message (Contention Resolution). If a user equipment ID carried in the contention resolution message received by the user equipment matches with the specific ID of the user equipment sent by the user equipment in the MSG3, or a carried contention detection identifier matches with the RRC sent by the user equipment in the MSG3, the random access succeeds.

Similar to the contention-based random access procedure, as shown in <FIG>, a non-contention random access procedure includes the following: First, a network side assigns, to a user equipment, a dedicated random access sequence, and the network side sends, to the user equipment, random access sequence assignment (Random Access Preamble assignment), that is, an MSG0. Next, the user equipment sends, to the network side over a selected PRACH, the dedicated random access sequence, that is, an MSG1, assigned to the user equipment. Finally, the network side sends a random access response, that is, an MSG2, to the user equipment. If the user equipment receives the random access response, the random access succeeds.

After the random access succeeds, the user equipment performs uplink data transmission. When the total power demanded for the uplink data transmission is greater than a maximum power transmission capability of the user equipment, that is, when power is limited, transmission power needs to be scaled. Priorities of transmission power of uplink channels when the power is limited are that: a priority of a PUSCH transmission over which does not include UCI (Uplink Control Information, uplink control information) is lower than a priority of a PUSCH transmission over which includes the UCI, and the priority of the PUSCH transmission over which includes the UCI is lower than a priority of a PUCCH (Physical Uplink Control Channel, physical uplink control channel).

The current random access procedure is applicable to a situation in which when multiple uplink carriers in carrier aggregation pass through the same path, all the carriers share the same timing advance. The random access procedure is only initiated in a primary serving cell, and in the random access procedure, a situation of other uplink transmission does not exist.

However, when the uplink carriers in the carrier aggregation pass through different paths, all the carriers no longer share the same timing advance, the random access procedure needs to be initiated in an auxiliary serving cell, and meanwhile, other uplink transmission may exist on another synchronized carrier (for example, uplink data transmission is performed in the primary serving cell while a random access procedure is performed in an auxiliary serving cell to obtain the timing advance used in uplink synchronization). At this time, the contention between the uplink data transmission and the random access procedure may occur in the current random access procedure.

<CIT> provides a signal transmission method in a long term evolution system, wherein the method comprises a step of: when the terminal requires transmitting physical random access channel PRACH in the uplink sub-frame or uplink pilot frequency time slot, and furthermore other uplink channel and/or uplink channel require to be transmitted in the sub-frame or uplink pilot frequency time slot, the terminal only transmits PRACH in the sub-frame or uplink pilot frequency time slot. The method can solve the problem of interference between PRACH and other uplink physical channel or uplink signal. The method can ensure the least effect to other uplink channel or signal of system when the terminal transmits scheduling request.

<CIT> relates to methods for scheduling of uplink transmission and generating transport blocks according to multiple received uplink assignments. Furthermore, it is also related to the implementation of these methods in hardware and software. To propose strategies for generating plural transport blocks within a given time constraint, the document introduces prioritization of the uplink assignments, so that multiple uplink assignments can be ranked in the mobile terminal in a priority order. The prioritization of the uplink assignments is used to determine the order in which the individual transport blocks corresponding to the uplink assignments are filled, respectively how the data of different logical channels is multiplexed to the transport blocks for transmission in the uplink. Another aspect is to suggest joint logical channel procedures that operate on virtual transport blocks accumulated from the received uplink assignments. One or more such joint logical channel procedure can be performed in parallel.

<CIT> discloses radio base station and mobile communication method. The radio base station (eNB) comprises: a transmission format deciding unit (<NUM>) for deciding a transmission format of uplink data signals in which HARQ is performed; a frequency resource deciding unit (<NUM>) for deciding a frequency resource of the uplink data signals; a transmission instructing unit (<NUM>) for instructing a new transmission and a retransmission of the uplink data signals via PDCCH; and an arrival acknowledgement information transmitting unit (<NUM>) for transmitting arrival acknowledgement information of the uplink data signals via PHICH. The arrival acknowledgement information transmitting unit (<NUM>) always transmits ACK as the arrival acknowledgement information when a subframe bundling has been applied to the uplink data signals.

<CIT> relates to a method and a communication network node for automatically tuning a PRACH configuration parameter in a communication network system comprising radio base stations each serving at least one cell and with which user equipments are communicating on uplink and downlink channels. The PRACH configuration parameter is used for defining the division of uplink resource blocks between PRACH and PUSCH. Load statistics on PRACH and PUSCH are collected used for determining a number of PRACH opportunities required per time unit. Then a new PRACH configuration parameter having said required number of PRACH opportunities per time unit is selected which is replacing the old PRACH configuration parameter.

<CIT> discloses a mobile station device, a wireless communication method, and a circuit device. A mobile station device (<NUM>) communicates with a base station device (<NUM>). The disclosed mobile station device (<NUM>) is provided with: a receiving unit (<NUM>) that receives a downlink control channel which contains information indicating a wireless resource for transmitting a contention-based signal; and a transmission unit (<NUM>) that transmits downlink channel quality information using a wireless resource allocated by the base station device. If the contention-based signal and the channel quality information collide in the same uplink time frame, the transmission unit (<NUM>) transmits at least one of the channel quality information and the contention-based signal.

<CIT> discloses a physical channel communication method for random access in a wireless communication system. A physical channel communication method and apparatus for random access in a cellular communication system including a plurality of relay nodes and user equipments using the same system information is provided. The physical channel communication method for random access in a wireless communication system includes receiving, by at least two relay nodes connected to a base station, system information containing a Physical Random Access Channel (PRACH) region allocation information for identifying user equipments attached to the relay nodes; receiving PRACHs for random accesses transmitted by the user equipments; and transmitting the PRACHs to the base station on relay node-specific resource regions according to the PRACH region allocation information.

Embodiments of the present invention provide a method for random access and an apparatus, which avoid contention between other uplink transmission and a random access procedure.

As can be seen from technical solutions provided by the embodiments of the present invention, it is implemented that transmission of the random access sequence and other uplink transmission are controlled to be successively performed, or it is implemented that transmission of the random access sequence and other uplink transmission are controlled to be simultaneously performed, which avoids contention between uplink transmission and a random access procedure in a parallel data random access procedure.

To illustrate the technical solutions according to the embodiments of the present invention more clearly, the accompanying drawings for describing the embodiments are introduced briefly in the following. Apparently, the accompanying drawings in the following description are only some embodiments of the present invention, and persons of ordinary skill in the art can derive other drawings from the accompanying drawings without creative efforts.

The technical solutions of the present invention are clearly and fully described in the following with reference to the accompanying drawings. It is obvious that the embodiments to be described are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

As an example not part of the invention but helpful for understanding the invention, a method for ensuring parallel data random access is provided, which includes:
controlling a random access sequence transmitted by a user equipment through a PRACH not to be sent in the same subframe with other uplink transmission.

Further, the method is applicable to a situation in which the PRACH and a PUCCH/PUSCH are in the same subframes of different carriers. When the uplink channel over which the other uplink transmission is performed includes a PUCCH and a PUSCH, a priority of the PRACH, a priority of the PUCCH and a priority of the PUSCH are controlled, so as to implement successive transmission of the random access sequence and the other uplink transmission.

Specifically, the priority of the PRACH is controlled to be lower than the priority of the PUCCH and the priority of the PUSCH, so that when a PRACH subframe for transmitting the random access sequence is selected, a subframe in which uplink transmission needs to be performed through the PUCCH and the PUSCH is not selected.

Specifically, the priority of the PRACH is controlled to be higher than the priority of the PUCCH and the priority of the PUSCH, so that when uplink transmission performed through the PUCCH and the PUSCH exists in a selected subframe in which the PRACH for transmitting the random sequence lies, the uplink transmission performed through the PUCCH and the PUSCH is cancelled.

Specifically, the priority of the PRACH is controlled to be higher than that of the PUSCH but lower than that of the PUCCH, so that when a PRACH subframe for transmitting the random access sequence is selected, a subframe in which uplink transmission needs to be performed through the PUCCH is not selected, and when uplink transmission performed through the PUSCH exists in the selected subframe in which the.

PRACH for transmitting the random sequence lies, the uplink transmission performed through the PUSCH is cancelled.

An embodiment of the present invention provides a method for ensuring parallel data random access, which includes:
when a random access sequence transmitted by a user equipment through a PRACH is sent in the same subframe with other uplink transmission, controlling a priority of transmission power of the PRACH and a priority of transmission power of an uplink channel over which the other uplink transmission is performed, when power is limited.

Further, when the uplink channel over which the other uplink transmission is performed includes a PUCCH and a PUSCH, a priority of transmission power of the PRACH, a priority of transmission power of the PUCCH and a priority of transmission power of the PUSCH when power is limited are controlled, so as to implement control of simultaneous transmission of the random access sequence and the other uplink transmission.

As an example not part of the invention but helpful for understanding the invention, a priority of transmission power of a PUSCH transmission over which does not include uplink control information UCI is controlled to be lower than a priority of transmission power of a PUSCH transmission over which includes the UCI, the priority of transmission power of the PUSCH transmission over which includes the UCI is controlled to be lower than a priority of transmission power of the PRACH, and the priority of transmission power of the PRACH is controlled to be lower than a priority of transmission power of the PUCCH.

In embodiments of the invention, a priority of transmission power of a PUSCH transmission over which does not include UCI is controlled to be lower than a priority of transmission power of a PUSCH transmission over which includes the UCI, the priority of transmission power of the PUSCH transmission over which includes the UCI is controlled to be lower than a priority of transmission power of the PUCCH, and the priority of transmission power of the PUCCH is controlled to be lower than a priority of transmission power of the PRACH.

As an alternative example not part of the invention but helpful for understanding the invention, a priority of transmission power of a PUSCH transmission over which does not include UCI is controlled to be lower than a priority of transmission power of the PRACH, the priority of transmission power of the PRACH is controlled to be lower than a priority of transmission power of a PUSCH transmission over which includes the UCI, and the priority of transmission power of the PUSCH transmission over which includes the UCI is controlled to be lower than a priority of transmission power of the PUCCH.

Based on the two methods for ensuring parallel data random access provided above, the method may further include:
when the user equipment transmits an MSG3 to a network side through a PUSCH in a contention-based random access procedure, based on priorities of transmission power of uplink channels when existing power is limited, that is, the priority of transmission power of the PUSCH transmission over which does not include the UCI is lower than a priority of transmission power of the PUSCH transmission over which includes the UCI, and the priority of transmission power of the PUSCH transmission over which includes the UCI is lower than a priority of transmission power of the PUCCH, controlling a priority of transmission power of the PUCCH, a priority of transmission power of the PUSCH transmission over which does not include the UCI, a priority of transmission power of the PUSCH transmission over which includes the UCI, and a priority of transmission power of the PUSCH transmitting the MSG3, when the power is limited, so that transmission of the MSG3 in the random access procedure and the other uplink transmission are simultaneously performed.

Specifically, the priority of transmission power of the PUSCH transmission over which includes the UCI is controlled to be equal to the priority of transmission power of the PUSCH transmitting the MSG3. With reference to the priorities of uplink channels when existing power is limited, transmission of the MSG3 in the random access procedure and the other uplink transmission are enabled to be simultaneously performed.

Further, when the user equipment transmits the MSG3 to the network side in the contention-based random access procedure, the MSG3 is transmitted through an assigned uplink resource in a received random access response.

The above method may also include: when the contention-based random access procedure is initiated in an auxiliary serving cell, selecting and sending a random access sequence in a group A; or, according to the loss of a current downlink path of the auxiliary serving cell, selecting and sending a random access sequence in a group A or a group B.

Specifically, when the contention-based random access procedure is initiated in an auxiliary serving cell, generally a random access procedure has been completed in a primary serving cell and other uplink transmission is being performed, so the network side may learn a situation of a buffer of the network side through a parameter (for example, a buffer buffer state) carried during the uplink transmission performed in the primary serving cell. Therefore, the user equipment in the auxiliary serving cell does not need to consider the size of a message to be sent, and only needs to select and send a random access sequence in the group A or the group B according to the loss of the current downlink path or to directly select and send a random access sequence in the group A. In this way, the network side may assign minimum grants (grant) before contention detection.

A third embodiment of the present invention also provides a user equipment. As shown in <FIG>, the user equipment includes a control unit <NUM> or a power control unit <NUM>.

The control unit <NUM> is configured to control a random access sequence transmitted by the user equipment through a physical random access channel PRACH not to be sent in the same subframe with other uplink transmission.

Further, when an uplink channel over which the other uplink transmission is performed includes a PUCCH and a PUSCH, the control unit <NUM> is configured to control a priority of the PRACH, a priority of the PUCCH and a priority of the PUSCH, so as to implement successive transmission of the random access sequence and the other uplink transmission.

Specifically, the control unit <NUM> is configured to control the priority of the PRACH to be lower than the priority of the PUCCH and the priority of the PUSCH, so that when a PRACH subframe for transmitting the random access sequence is selected, a subframe in which uplink transmission needs to be performed through the PUCCH and the PUSCH is not selected.

The power control unit <NUM> is configured to, when a random access sequence transmitted by the user equipment through a PRACH is sent in the same subframe with other uplink transmission, control a priority of transmission power of the PRACH and a priority of transmission power of an uplink channel over which the other uplink transmission is performed, when power is limited.

Further, when the uplink channel over which the other uplink transmission is performed includes a PUCCH and a PUSCH, the power control unit <NUM> is configured to control a priority of transmission power of the PRACH, a priority of transmission power of the PUCCH and a priority of transmission power of the PUSCH when the power is limited, so as to implement control of simultaneous transmission of the random access sequence and the other uplink transmission.

Specifically, the power control unit <NUM> is configured to control a priority of transmission power of a PUSCH transmission over which does not include uplink control information UCI to be lower than a priority of transmission power of a PUSCH transmission over which includes the UCI, the priority of transmission power of the PUSCH transmission over which includes the UCI to be lower than a priority of transmission power of the PRACH, and the priority of transmission power of the PRACH to be lower than a priority of transmission power of the PUCCH.

When the user equipment transmits an MSG3 to a network side in a contention-based random access procedure, the user equipment may also include a transmitting unit, configured to transmit the MSG3 through an assigned uplink resource in a received random access response.

When the contention-based random access procedure is initiated in an auxiliary serving cell, the user equipment may also include a sending unit, configured to select and send a random access sequence in a group A; or, according to the loss of a current downlink path of the auxiliary serving cell, select and send a random access sequence in a group A or a group B.

The specific implementation manners of processing functions of the units included in the user equipment are described in the foregoing method embodiments, which are not described herein again.

It should be noted that, the units included in the above node embodiment are divided just according to logical functions, but the present invention is not limited to the division, as long as corresponding functions can be realized; and the specific names of the functional units are merely provided for the purpose of distinguishing the units from one another, but not intended to limit the protection scope of the present invention.

Additionally, persons of ordinary skill in the art should understand that, all of or a part of the steps in the method according to the embodiments may be implemented by a program instructing relevant hardware. The corresponding program may be stored in a computer readable storage medium. The storage medium may be a read-only memory, a magnetic disk, or an optical disk.

In a fourth example not part of the invention, a method for ensuring parallel data random access is provided, and the method includes:.

In a first further development of the method according to the fourth example, when the uplink channel over which the other uplink transmission is performed comprises a physical uplink control channel PUCCH and a physical uplink shared channel PUSCH, the controlling the random access sequence transmitted by the user equipment through the physical random access channel PRACH not to be sent with the other uplink transmission in the same subframe comprises:.

In a second further development of the method according to the fourth example, when the uplink channel over which the other uplink transmission is performed comprises a physical uplink control channel PUCCH and a physical uplink shared channel PUSCH, the controlling the priority of transmission power of the PRACH and the priority of transmission power of the uplink channel over which the other uplink transmission is performed, when power is limited comprises:.

In a third further development of the method according to the first or the second further development of the method, when the user equipment transmits an MSG3 to a network side through a PUSCH in a contention-based random access procedure, controlling a priority of transmission power of the PUCCH, a priority of transmission power of the PUSCH transmission over which does not comprise UCI, a priority of transmission power of the PUSCH transmission over which comprises the UCI, and a priority of transmission power of the PUSCH transmitting the MSG3 when power is limited, so that transmission of the MSG3 in the random access procedure and the other uplink transmission are simultaneously performed, wherein.

In a fourth further development of the method according to the fourth example or any further development of the method, the method further includes:
when the user equipment transmits an MSG3 to a network side in a contention-based random access procedure, transmitting the MSG3 through an assigned uplink resource in a received random access response.

In a fifth further development of the method according to the fourth example or any further development of the method, the method further includes:
when a contention-based random access procedure is initiated in an auxiliary serving cell, selecting and sending a random access sequence in a group A; or, according to loss of a current downlink path of the auxiliary serving cell, selecting and sending a random access sequence in a group A or a group B.

In a fifth example not part of the invention, a user equipment is provided, and the user equipment includes:.

In a first further development of the user equipment according to the fifth example, when the uplink channel over which the other uplink transmission is performed comprises a physical uplink control channel PUCCH and a physical uplink shared channel PUSCH, the control unit is configured to:.

In a second further development of the user equipment according to the fifth example, when the uplink channel over which the other uplink transmission is performed comprises a physical uplink control channel PUCCH and a physical uplink shared channel PUSCH, the power control unit is configured to:.

In a third further development of the user equipment according to the first or the second further development of the user equipment, when the user equipment transmits an MSG3 to a network side through a PUSCH in a contention-based random access procedure, the user equipment further comprises a power assignment unit, configured to control a priority of transmission power of the PUCCH, a priority of transmission power of the PUSCH transmission over which does not comprise UCI, a priority of transmission power of the PUSCH transmission over which comprises the UCI, and a priority of transmission power of the PUSCH transmitting the MSG3 when power is limited, so that transmission of the MSG3 in the random access procedure and the other uplink transmission are simultaneously performed, wherein.

In a fourth further development of the user equipment according to the fifth example or any further development of the user equipment, when the user equipment transmits an MSG3 to a network side in a contention-based random access procedure, the user equipment further comprises a transmitting unit, configured to transmit the MSG3 through an assigned uplink resource in a received random access response.

In a fifth further development of the user equipment according to the fifth example or any further development of the user equipment, when a contention-based random access procedure is initiated in an auxiliary serving cell, the user equipment further comprises a sending unit, configured to select and send a random access sequence in a group A; or, according to loss of a current downlink path of the auxiliary serving cell, select and send a random access sequence in a group A or a group B.

The user equipment enables a random access sequence and other uplink transmission to be successively transmitted by controlling the random access sequence transmitted through a PRACH not to be sent in the same subframe with the other uplink transmission. In the embodiments of the present invention, the user equipment enables a random access sequence and other uplink transmission to be simultaneously transmitted by controlling the priority of transmission power of a PRACH and the priority of transmission power of an uplink channel over which the other uplink transmission is performed, when power is limited, thereby avoiding contention between the other uplink transmission and the random access procedure. In addition, an MSG3 is transmitted through an assigned uplink resource in a received random access response in a contention-based random access procedure, which avoids the possibility that the user equipment obtains a wrong timing advance when the MSG3 is successfully sent in another synchronized cell, thereby ensuring the accuracy of contention detection in the random access procedure. Meanwhile, when the contention-based random access procedure is initiated by a user equipment in an auxiliary serving cell, the user equipment may directly select and send a random access sequence in a group A or select and send a random access sequence in a group A or a group B just according to the loss of a current downlink path, thereby saving a judgment process and achieving more accurate selection.

Claim 1:
A method for ensuring parallel data random access, comprising:
transmitting, by a user equipment, a random access sequence through a physical random access channel, PRACH, with other uplink transmission in a same subframe of different carriers,
wherein the other uplink transmission comprises physical uplink control channel, PUCCH, and a physical uplink shared channel, PUSCH, and
wherein when power is limited, a priority of transmission power of the PRACH and a priority of transmission power of an uplink channel over which the other uplink transmission is performed are controlled by the user equipment,
wherein a priority of transmission power of the PRACH and a priority of transmission power of an uplink channel over which the other uplink transmission is performed are controlled by the user equipment as follows:
a priority of transmission power of a PUSCH that does not include uplink control information, UCI, is controlled to be lower than a priority of transmission power of a PUSCH that includes UCI, the priority of transmission power of the PUSCH that includes the UCI is controlled to be lower than a priority of transmission power of the PUCCH, and the priority of transmission power of the PUCCH is controlled to be lower than a priority of transmission power of the PRACH.