CN102083135B - Method and device for transmitting relay downlink data in long-term evolution advanced (LTE-A) system - Google Patents
Method and device for transmitting relay downlink data in long-term evolution advanced (LTE-A) system Download PDFInfo
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Abstract
The embodiment of the invention discloses a method and device for transmitting relay downlink data in a long term evolution advanced (LTE-A) system, relates to the technical field of wireless communication, and aims to solve the problem that the completeness of the downlink control channel data transmitted by relay downlink cannot be ensured, and a terminal has an error in control channel detection. The method comprises the following steps: determining whether a time interleaving part exists between a sub-frame M-1 and an adjusted sub-frame M after a relay device adjusts downlink transmittingtiming of the relay device to the terminal in the sub-frame M; forbidding transmitting or receiving a signal in the time interleaving part between the sub-frame M-1 and the adjusted sub-frame M if the time interleaving part exists between the sub-frame M-1 and the adjusted sub-frame M; and transmitting a signal to be transmitted in the sub-frame to the terminal from the adjusted sub-frame M. Therefore, the method ensures the completeness of the downlink control channel data transmitted by the relay downlink so as to avoid the problem that the terminal has an error in control channel detection.
Description
Technical Field
The present invention relates to the field of wireless communication technologies, and in particular, to a method and an apparatus for sending relay downlink data in a long term evolution upgrade system.
Background
In a long term evolution advanced (LTE-a) system, in order to improve system throughput and increase network coverage, a Relay Node (RN) is introduced, as shown in fig. 1, a base station (eNB) is connected to a Core Network (CN) through a wired interface, and the RN is connected to the eNB through a wireless interface; the terminal (UE) is connected to the RN or eNB through a wireless interface. The link between the RN and the base station is referred to as a backhaul (backhaul) link, and the link between the RN and the UE is referred to as an access link.
For either Time Division Duplex (TDD) or Frequency Division Duplex (FDD) systems, a signal transmitted from the eNB to the RN on the backhaul link requires a certain time delay, which is directly related to the distance between the eNB and the RN. When viewed from the RN side, the received downlink signal of the backhaul link is subjected to the time delay, as shown in fig. 2.
As can be seen from fig. 2, the downlink of the relay backhaul link achieves synchronization initialization and synchronization tracking with the eNB downlink through downlink signals (such as a primary synchronization signal, a secondary synchronization signal, and a pilot signal) transmitted by the eNB.
Fig. 3 shows that the downlink transmission time of the RN access link is synchronized with the downlink reception time of the RN backhaul link. If the RN is regarded as an independent eNB, the downlink transmission of the eNB and the downlink transmission of the RN are not synchronized.
According to the current timing situation of the relay downlink access link, there is a situation that the relay adjusts the downlink of the access link to ensure the synchronization of the downlink transmission of the relay access link and the backhaul downlink transmission of the eNB, as shown in fig. 4. And the relay equipment adjusts the downlink sending timing of the access link according to the downlink timing adjusting command sent by the base station.
In the process of implementing the invention, the inventor finds that the following technical problems exist in the prior art:
after the relay device adjusts the downlink transmission timing of the access link according to the downlink timing adjustment command sent by the base station, the timing adjustment may cause a time overlapping portion to exist between the subframe n and the adjusted subframe n +1, and currently, a signal is not sent in the time overlapping portion of the subframe n +1, and a signal that needs to be sent in the subframe n is sent in the subframe n. No signal is sent in the time overlapping portion of the subframe n +1, and since the time overlapping portion of the subframe n +1 is used for sending a control channel signal, such as a Physical Downlink Control Channel (PDCCH) signal, to the terminal, no signal is sent in the time overlapping portion of the subframe n +1, so that the integrity of the downlink control channel data sent by the relay downlink cannot be guaranteed, and further, an error occurs in the detection of the control channel in the subframe n +1 by the terminal.
Disclosure of Invention
The embodiment of the invention provides a relay downlink data sending method and equipment in an LTE-A system, which are used for solving the problem that the integrity of downlink control channel data sent by relay downlink is not ensured, so that a terminal detects a control channel to generate errors.
A method for transmitting relay downlink data in an LTE-A system comprises the following steps:
the relay equipment adjusts the downlink sending timing of the relay equipment to the terminal in the subframe M, and determines whether a time overlapping part exists between the subframe M-1 and the adjusted subframe M;
and when determining that the subframe M-1 and the adjusted subframe M have the time overlapping part, the relay equipment prohibits the subframe M-1 from transmitting or receiving signals with the time overlapping part of the adjusted subframe M, and transmits signals needing to be transmitted in the subframe to the terminal in the adjusted subframe M.
A relay device, the device comprising:
a downlink timing adjustment unit, configured to adjust, in the subframe M, a downlink transmission timing from the relay device to the terminal;
an overlap determining unit for determining whether there is a time overlap portion between the subframe M-1 and the adjusted subframe M;
and the processing unit is used for forbidding the signal to be transmitted or received in the time overlapping part of the subframe M-1 and the adjusted subframe M when the overlapping determining unit determines that the time overlapping part exists between the subframe M-1 and the adjusted subframe M, and transmitting the signal which needs to be transmitted in the subframe to the terminal in the adjusted subframe M.
In the invention, after the subframe M adjusts the downlink sending timing of the relay equipment to the terminal, the relay equipment determines whether a time overlapping part exists between the subframe M-1 and the adjusted subframe M, if so, the relay equipment prohibits sending or receiving signals in the subframe M-1 and the time overlapping part of the adjusted subframe M, and sends signals needing to be sent in the subframe to the terminal in the adjusted subframe M. Therefore, in the invention, after the subframe M adjusts the downlink sending timing of the relay equipment to the terminal, the relay equipment does not send or receive signals in the time overlapping part of the subframe M-1 and the adjusted subframe M, and sends signals needing to be sent in the subframe to the terminal in the adjusted subframe M, thereby ensuring the integrity of downlink control channel data sent in the downlink relay, and further avoiding the problem that the terminal detects errors in the control channel.
Drawings
Fig. 1 is a schematic diagram of an LTE-a system in the prior art;
fig. 2 is a schematic diagram of time delay of a relay receiving a downlink backhaul link signal in the prior art;
fig. 3 is a timing relationship between an access link and a backhaul link in the prior art;
fig. 4 is a schematic diagram illustrating downlink timing synchronization between a relay access link and a base station backhaul link in the prior art;
FIG. 5 is a schematic flow chart of a method provided by an embodiment of the present invention;
FIG. 6A is a schematic diagram of a subframe according to a first embodiment of the present invention;
FIG. 6B is a schematic diagram of another subframe according to the first embodiment of the present invention;
FIG. 7A is a diagram of a subframe according to a second embodiment of the present invention;
FIG. 7B is a schematic diagram of another subframe according to the second embodiment of the present invention;
FIG. 8A is a schematic diagram of a subframe according to a third embodiment of the present invention;
FIG. 8B is a schematic diagram of another subframe according to the third embodiment of the present invention;
FIG. 9A is a schematic diagram of a subframe according to a fourth embodiment of the present invention;
FIG. 9B is a schematic diagram of another subframe according to the fourth embodiment of the present invention;
FIG. 10A is a schematic diagram of a subframe according to a fifth embodiment of the present invention;
FIG. 10B is a schematic diagram of another subframe according to the fifth embodiment of the present invention;
fig. 11 is a schematic diagram of an RN structure according to an embodiment of the present invention.
Detailed Description
In order to solve the problem that the integrity of downlink control channel data transmitted by a relay downlink is not guaranteed, so that a terminal detects a control channel and generates errors, the embodiment of the invention provides a method for transmitting relay downlink data in an LTE-A system.
Referring to fig. 5, a method for sending relay downlink data in an LTE-a system according to an embodiment of the present invention specifically includes the following steps:
step 50: the relay equipment adjusts the downlink sending timing of the relay equipment to the terminal in the subframe M;
step 51: after the relay equipment adjusts the downlink sending timing of the relay equipment to the terminal, whether a time overlapping part exists between the subframe M-1 and the adjusted subframe M is determined.
Step 52: and when determining that the subframe M-1 and the adjusted subframe M have the time overlapping part, the relay equipment prohibits the subframe M-1 from transmitting or receiving signals with the time overlapping part of the adjusted subframe M, and transmits signals needing to be transmitted in the subframe to the terminal in the adjusted subframe M.
In step 50, the base station sends an access link downlink subframe sending timing adjustment command to the relay device, and the relay device adjusts the downlink sending timing of the relay device to the terminal in the subframe M according to the command, which can be specifically realized as follows:
firstly, a base station generates an access link downlink subframe sending timing adjustment command, wherein the access link downlink subframe sending timing adjustment command is a command used by relay equipment for adjusting the downlink sending timing of the relay equipment so as to synchronize the access link downlink subframe sending timing of the relay equipment with the base station downlink subframe sending timing;
here, the base station may generate the access link downlink subframe transmission timing adjustment command according to a reception time when the signal transmitted by the relay device is received. Of course, the base station may also generate the access link downlink subframe transmission timing adjustment command at any other timing when the downlink transmission timing of the relay device needs to be adjusted, for example, after the base station adjusts the downlink transmission timing of the backhaul link, in order to ensure that the access link downlink subframe transmission timing of the relay device is synchronized with the base station downlink subframe transmission timing, the downlink transmission timing of the relay device needs to be adjusted at the same time, so as to generate the access link downlink subframe transmission timing adjustment command to be transmitted to the relay device.
Then, the base station sends the access link downlink subframe sending timing adjustment command to the relay equipment so as to instruct the relay equipment to adjust the downlink sending timing of the relay equipment according to the access link downlink subframe sending timing adjustment command.
The base station generates an access link downlink subframe sending timing adjustment command according to the time of receiving the signal sent by the relay device, and specific scenarios may include the following three types:
the first method comprises the following steps: and the base station generates an access link downlink subframe sending timing adjustment command according to the receiving time of a random access signal sent by the relay equipment through a Physical Random Access Channel (PRACH) in the initial access process.
And the second method comprises the following steps: before a base station generates an access link downlink subframe and sends a timing adjustment command, the base station sends a random access instruction command to relay equipment; after receiving the random access instruction command, the relay equipment sends a random access signal to the base station through the PRACH; and the base station generates a downlink subframe sending timing adjustment command of the access link according to the receiving time of the received random access signal.
Thirdly, the base station generates a timing adjustment command for sending the downlink subframe of the access link according to the receiving time of other signals except the random access signal sent by the relay equipment. For example, the access link downlink subframe transmission timing adjustment command is generated according to the reception time of the signal transmitted by the relay device after the random access is completed.
The specific manner of generating the access link downlink subframe sending timing adjustment command by the base station may be as follows:
firstly, the base station determines the time difference delta between the time of receiving the signal transmitted by the relay equipment in the uplink subframe k and the starting time of the subframe k of the base stationDL；
Then, the base station divides the time difference Δ according to the quantization step sizeDLOr time difference ΔDLQuantizing the half of the data to obtain timing advance quantized data; for example, the time difference Δ may be expressed by the following formula oneDLIs quantized, the time difference Δ can be calculated by the following equation twoDLAnd (3) quantization:
the formula I is as follows: timing advance quantized data ceil (ΔDL/K/2), or,
timing advance quantized data-floor (Δ)DL/K/2)；
The formula II is as follows: timing advance quantized data ceil (ΔDLK), or (ii) in the alternative,
timing advance quantized data floor (Δ DL/K);
wherein ceil denotes rounding up, floor denotes rounding down, and K is the quantization step. For example, in 3GPP LTE/LTE-a, the quantization step is 16Ts, and Ts is 1/(15000 × 2048) seconds, which is the system minimum time unit.
And finally, the base station generates an access link downlink subframe sending timing adjustment command representing the timing advance quantized data. For example, the timing advance quantized data is represented by 11 bits or 6 bits in binary.
After receiving a timing adjustment command sent by a base station for sending downlink subframes of an access link at a subframe n, the relay equipment determines whether the subframe n + k is a downlink subframe, and if so, adjusts the downlink sending timing of the relay equipment to a terminal at the subframe n + k; otherwise, the downlink sending timing of the relay equipment to the terminal is adjusted in the first downlink subframe after the subframe n + k. Specifically, first, the relay device determines a timing advance for downlink transmission of the relay device according to a downlink subframe transmission timing adjustment command of an access link, and then adjusts downlink transmission timing of the relay device according to the timing advance in a subframe n + k or a first downlink subframe after the subframe n + k. k is an integer of not less than 0. For example, k may take on a value of 6.
If the relay device receives a timing adjustment command sent by the base station for sending a downlink subframe of an access link after initiating random access through the PRACH, the relay device may determine a timing advance TA sent by the relay device in a downlink according to the following formula one or formula two:
the formula I is as follows: TA ═ TAC × K;
the formula II is as follows: TA TAC K/2;
the TAC is timing advance quantized data represented by a timing adjustment command sent by a downlink subframe of an access link, and K is a quantization step used when the base station obtains the timing advance quantized data.
The time difference delta is calculated according to the quantization step size at the base stationDLWhen half of the time difference is quantized, the relay device may determine TA by using formula one, and the base station may determine the time difference Δ according to the quantization stepDLWhen performing quantization, the relay device may determine TA using equation two.
If the relay equipment receives a timing adjustment command sent by the base station for sending the downlink subframe of the access link after the random access is finished, the relay equipment determines the timing advance TA sent by the relay equipment in the downlink according to a formula three or a formula four as follows:
the formula III is as follows: TA ═ TAold+(TAC-2N-1)*K；
The formula four is as follows: TA ═ TAold+(TAC-(2N-1-1))*K/2；
Wherein, TAC is the timing advance quantization data represented by the timing adjustment command sent by the downlink subframe of the access link, K is the quantization step used by the base station to obtain the timing advance quantization data, N is the bit number used by the downlink subframe of the access link to send the timing adjustment command, and TAoldAnd the timing advance value of the downlink transmission of the relay equipment is determined for the last time before the relay equipment receives the timing adjustment command of the downlink subframe transmission of the access link. The quantization step size may be 16 × Ts, which is the minimum time unit of the LTE-a system. N may be 6 or 11.
The time difference delta is calculated according to the quantization step size at the base stationDLWhen the half of the time difference is quantized, the relay device may determine TA by using formula three, and the base station may determine the time difference Δ according to the quantization stepDLWhen performing quantization, the relay device may determine TA using equation four.
The relay device adjusts the downlink transmission timing of the relay device according to the determined timing advance TA in the subframe n + k or the first downlink subframe after the subframe n + k, and the specific implementation may be as follows:
if the timing advance is a positive value, the relay equipment sends the timing advance TA size to the downlink subframe of the access link of the relay equipment in the subframe n + k or the first downlink subframe after the subframe n + k, and if the timing advance is a negative value, the relay equipment sends the timing delay TA size to the downlink subframe of the access link of the relay equipment in the subframe n + k or the first downlink subframe after the subframe n + k.
In step 52, the signal is prohibited from being transmitted or received in the time overlapping part of the subframe M-1 and the adjusted subframe M, which includes the following four cases:
first, when the subframe M-1 is an uplink subframe of the backhaul link, the relay device prohibits a time overlapping portion with the adjusted subframe M in the subframe M-1 from transmitting a signal to the base station.
Secondly, when the subframe M-1 is a downlink subframe of the backhaul link, the relay device prohibits the time overlapping part of the subframe M-1 and the adjusted subframe M from receiving the signal transmitted by the base station.
Thirdly, when the subframe M-1 is an uplink subframe of the access link, the relay equipment prohibits the time overlapping part of the subframe M-1 and the adjusted subframe M from receiving the signal sent by the terminal.
Fourthly, when the subframe M-1 is a downlink subframe of the access link, the relay equipment prohibits the time overlapping part of the subframe M-1 and the adjusted subframe M from transmitting signals to the terminal.
In step 52, the adjusted subframe M sends a signal that needs to be sent in the subframe to the terminal, which may specifically be as follows:
sending a PDCCH signal to the terminal in the adjusted subframe M; or,
and sending the PDCCH signal and the service data signal to the terminal in the adjusted subframe M, namely sending a complete subframe signal to the terminal in the subframe M.
The present invention will be described in detail with reference to the following examples:
the main idea of this patent is: in subframe n, the relay device determines that the downlink transmission timing to the terminal needs to be adjusted, that is, a received downlink subframe transmission timing adjustment command of an access link from the base station is received in subframe n. And the relay equipment performs downlink timing adjustment in the subframe n + k. If the subframe n + k-1 and the adjusted n + k are overlapped due to the timing adjustment, no signal is transmitted in the overlapped part of the subframe n + k in the subframe n + k-1, and all signals needing to be transmitted are transmitted in the subframe n + k. Where k > 6.
The first embodiment is as follows:
in subframe n, the relay device determines that downlink transmission timing to the terminal needs to be adjusted in subframe n, and the relay device performs downlink timing adjustment in subframe n + k.
As shown in fig. 6A, a subframe configuration diagram before performing downlink timing adjustment for a relay device is shown; the subframe n + k-1 is an uplink subframe of a backhaul link, and both the subframe n + k-1 and the subframe n + k are subframes for relay transmission of signals.
A guard time interval (GP) of at least 20us exists at the end of a subframe of a backhaul uplink, if the length of downlink timing adjustment performed by the relay device is not greater than 20us, there is no influence on the backhaul uplink, and if the length of timing adjustment is greater than 20us, there may be an influence on the backhaul uplink, and a partial signal of the last OFDM symbol of the backhaul uplink cannot be transmitted.
After the relay device performs downlink timing adjustment, there may be a time overlapping portion between the subframe n + k-1 and the adjusted subframe n + k, and the time overlapping portion may be located in a circle in fig. 6A. At this time, no signal is transmitted in the time overlapping portion of the subframe n + k-1 and the adjusted subframe n + k, and the complete signal of one subframe is transmitted in the subframe n + k.
Fig. 6B is different from fig. 6A in that, in fig. 6B, after the relay device performs downlink timing adjustment, only the PDCCH signal is transmitted in subframe n + k.
Example two:
in subframe n, the relay device determines that downlink transmission timing to the terminal needs to be adjusted, and the relay device performs downlink timing adjustment in subframe n + k.
As shown in fig. 7A, a subframe configuration diagram before performing downlink timing adjustment for a relay device is shown; the subframe n + k-1 is a downlink subframe of the access link, and the subframe n + k-1 and the subframe n + k are subframes for relay sending signals.
After the relay device performs downlink timing adjustment, there may be a time overlapping portion between the subframe n + k-1 and the adjusted subframe n + k, and the time overlapping portion may be located in a circle in fig. 7A. At this time, no signal is sent in the subframe n + k-1 and the time overlapping part of the adjusted subframe n + k, and a complete signal of one subframe is sent in the subframe n + k, so that the integrity of the signal sent to the UE in the subframe n + k is ensured.
Fig. 7B is different from fig. 7A in that, in fig. 7B, after the relay device performs downlink timing adjustment, only the PDCCH signal is transmitted in subframe n + k.
Example three:
in subframe n, the relay device determines that downlink transmission timing to the terminal needs to be adjusted in subframe n, and the relay device performs downlink timing adjustment in subframe n + k.
As shown in fig. 8A, a subframe configuration diagram before performing downlink timing adjustment for a relay device is shown; the subframe n + k-1 is a downlink subframe of the backhaul link, the subframe n + k-1 is a subframe in which the RN receives a signal, and the subframe n + k is a subframe in which the RN transmits a signal.
And a transceiving switching time exists in the last part of the subframe n + k-1, the length of the transceiving switching time is at least 20us, if the length of downlink timing adjustment of the relay equipment is not more than 20us, the backhaul downlink is not influenced, and if the length of the timing adjustment is more than 20us, the backhaul downlink can be influenced, and a part of signals of the last OFDM symbol of the backhaul downlink cannot be received.
After the relay device performs downlink timing adjustment, there may be a time overlapping portion between the subframe n + k-1 and the adjusted subframe n + k, and the time overlapping portion may be located in a circle in fig. 8A. At this time, no signal is sent in the subframe n + k-1 and the time overlapping part of the adjusted subframe n + k, and a complete signal of one subframe is sent in the subframe n + k, so that the integrity of the signal sent to the UE in the subframe n + k is ensured.
Fig. 8B is different from fig. 8A in that, in fig. 8B, after the relay device performs downlink timing adjustment, only the PDCCH signal is transmitted in subframe n + k.
Example four:
in subframe n, the relay device determines that downlink transmission timing to the terminal needs to be adjusted in subframe n, and the relay device performs downlink timing adjustment in subframe n + k.
As shown in fig. 9A, a subframe configuration diagram before performing downlink timing adjustment for a relay device is shown; and a subframe n + k-1 is an uplink subframe of the access link, a subframe n + k-1 is a subframe of the RN for receiving the signal, and a subframe n + k is a subframe of the relay for transmitting the signal.
And a transceiving conversion time exists in the last part of the subframe n + k-1, the length of the transceiving conversion time is at least 20us, if the length of the downlink timing adjustment of the relay equipment is not more than 20us, no influence is caused on the uplink of the access link, and if the length of the timing adjustment is more than 20us, the influence on the uplink of the access link can be caused, and partial signals of the last OFDM symbol of the uplink of the access link cannot be received.
After the relay device performs downlink timing adjustment, there may be a time overlapping portion between the subframe n + k-1 and the adjusted subframe n + k, and the time overlapping portion may be located in a circle in fig. 9A. At this time, no signal is sent in the subframe n + k-1 and the time overlapping part of the adjusted subframe n + k, and a complete signal of one subframe is sent in the subframe n + k, so that the integrity of the signal sent to the UE in the subframe n + k is ensured.
Fig. 9B is different from fig. 9A in that, in fig. 9B, after the relay device performs downlink timing adjustment, only the PDCCH signal is transmitted in subframe n + k.
From the above analysis, in the case that the subframe n + k before which the relay device sends a signal to the UE is the access downlink subframe n + k-1, there is no extra guard time after the subframe n + k-1, and therefore if the two downlink subframes overlap, the data part content of the subframe n + k-1 cannot be sent. Although this will probably cause the data demodulation performance of the subframe n + k-1 to deteriorate, the integrity of the control channel of the subframe n + k is ensured, and a guarantee is provided for the relay-serving UE to correctly detect the downlink control channel of the access link.
When the downlink subframe n + k where the relay sends signals to the UE is not accessed before the downlink subframe, the subframe n + k-1 can provide a guard time interval of at least 20us, and the time interval provides possibility for avoiding collision between the subframe n + k and the subframe n + k. However, if the timing adjustment command range is large, there is still a possibility of collision between the two subframes. Therefore, the partial data of the subframe n + k-1 may not be able to be completely transmitted, and thus its false detection probability may increase. But the completeness of the control channel of the subframe n + k is ensured, and the guarantee is provided for the UE of the relay service to correctly detect the downlink control channel of the access link.
The above example shows the case where the backhaul of the relay and the downlink timing of the relay to the UE are both completely synchronized with the base station, and the method provided by this patent can also be applied to the case where the backhaul link and the base station are not completely synchronized. In this case, the specific use of each subframe may vary, but does not affect the application of the method of the present patent. Fig. 10A and 10B show a typical example. And the relay backhaul uplink carries out certain timing offset forward according to the timing advance, so that the time interval between the subframe n + k-1 and the subframe n + k is further increased to be the sum of the guard time interval GP and the propagation delay. The possibility of subframe n + k overlapping with subframe n + k-1 due to timing adjustments for subframe n + k is further reduced. If so, the overlapping portion of subframe n + k-1 is still not transmitted, and the entire subframe n + k is transmitted. Fig. 10A and fig. 10B show the case where the downlink transmitted by the relay to its UE is a complete subframe or only a PDCCH signal, respectively.
Further, from the above analysis, if the downlink timing adjustment is performed in the subframe n + k, and the subframe n + k-1 is not a downlink subframe for relaying signals to the UE, there is an additional guard time interval (greater than or equal to 20 us). The probability of overlap between subframes n + k-1 and n + k is significantly reduced, and therefore, subframe n + k where timing adjustment begins may be selected if its previous subframe is not a downlink subframe where the relay transmits signals to the UE.
The communication flow between the eNB and the relay device is as follows:
the eNB side:
step 1: the base station calculates a timing adjustment amount used when the relay equipment adjusts downlink sending timing of the UE;
step 2: the base station sends a downlink timing adjustment command representing the timing adjustment amount to the relay equipment;
a relay side:
step 1: the relay equipment obtains a downlink timing adjustment command;
step 2: the relay equipment calculates the timing adjustment amount according to the downlink timing adjustment command;
and step 3: and the relay equipment performs downlink timing adjustment on a subframe n + k according to the timing adjustment amount, wherein k is equal to 6. The relay equipment judges that if a time overlapping part exists between the subframe n + k-1 and the adjusted subframe n + k, the overlapping part of the subframe n + k-1 and the adjusted subframe n + k does not send or receive signals, and the adjusted subframe n + k sends signals needing to be sent.
Referring to fig. 11, an embodiment of the present invention further provides a relay device, where the relay device includes:
a downlink timing adjustment unit 110, configured to adjust downlink transmission timing of the relay device to the terminal in the subframe M;
an overlap determining unit 111, configured to determine whether a time overlap portion exists between the subframe M-1 and the adjusted subframe M;
and a processing unit 112, configured to prohibit sending or receiving a signal in the subframe M-1 in the time overlapping portion with the adjusted subframe M when the overlap determination unit determines that the time overlapping portion exists between the subframe M-1 and the adjusted subframe M, and send a signal required to be sent in the subframe to the terminal in the adjusted subframe M.
The processing unit 112 is configured to:
and when the subframe M-1 is an uplink subframe of a backhaul link, prohibiting a time overlapping part of the subframe M-1 and the adjusted subframe M from transmitting a signal to a base station.
The processing unit 112 is configured to:
and when the subframe M-1 is a downlink subframe of the backhaul link, prohibiting a time overlapping part of the subframe M-1 and the adjusted subframe M from receiving a signal sent by the base station.
The processing unit 112 is configured to:
and when the subframe M-1 is an uplink subframe of an access link, prohibiting a signal sent by a terminal from being received in a time overlapping part of the subframe M-1 and the adjusted subframe M.
The processing unit 112 is configured to:
and when the subframe M-1 is a downlink subframe of the access link, prohibiting a time overlapping part of the subframe M-1 and the adjusted subframe M from transmitting a signal to the terminal.
The processing unit 112 is configured to:
sending a Physical Downlink Control Channel (PDCCH) signal to a terminal in the adjusted subframe M; or,
and sending a Physical Downlink Control Channel (PDCCH) signal and a service data signal to the terminal in the adjusted subframe M.
The downlink timing adjustment unit 110 is configured to:
receiving a timing adjustment command sent by a base station for sending a downlink subframe of an access link at a subframe n, determining whether the subframe n + k is a downlink subframe, and if so, adjusting the downlink sending timing of the relay equipment to a terminal at the subframe n + k; otherwise, adjusting the downlink sending timing of the relay equipment to the terminal at the first downlink subframe after the subframe n + k; and k is an integer not less than 0. For example, k may take on a value of 6.
In the invention, relay uplink refers to the relay device sending signals to the eNB, relay downlink refers to the relay device sending signals to the UE, eNB downlink refers to the eNB sending signals to the relay device, eNB uplink refers to the eNB receiving signals from the relay device, uplink of the UE served by the relay device refers to the UE sending signals to the relay device, and downlink of the UE served by the relay device refers to the UE receiving signals from the relay device.
In conclusion, the beneficial effects of the invention include:
in the scheme provided by the embodiment of the invention, the relay equipment determines whether a time overlapping part exists between the subframe M-1 and the adjusted subframe M or not after the subframe M adjusts the downlink transmission timing of the relay equipment to the terminal according to the received downlink subframe transmission timing adjustment command of the access link from the base station, and if so, prohibits the time overlapping part of the subframe M-1 and the adjusted subframe M from transmitting or receiving signals, and transmits signals required to be transmitted in the subframe to the terminal in the adjusted subframe M. Therefore, in the method, after the subframe M adjusts the downlink transmission timing of the relay device to the terminal, the relay device does not transmit or receive signals in the subframe M-1 and the time overlapping part of the adjusted subframe M, and transmits the signals needing to be transmitted in the subframe to the terminal in the adjusted subframe M, so that the integrity of downlink control channel data transmitted by the relay downlink is ensured, and the problem that the terminal detects errors in the control channel is avoided.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (16)
1. A method for sending relay downlink data in a long term evolution advanced LTE-A system is characterized by comprising the following steps:
the relay equipment adjusts the downlink sending timing of the relay equipment to the terminal in the subframe M;
the relay equipment determines whether a time overlapping part exists between the subframe M-1 and the adjusted subframe M;
and when determining that the subframe M-1 and the adjusted subframe M have the time overlapping part, the relay equipment prohibits the subframe M-1 from transmitting or receiving signals with the time overlapping part of the adjusted subframe M, and transmits signals needing to be transmitted in the subframe to the terminal in the adjusted subframe M.
2. The method of claim 1, wherein the prohibiting transmission or reception of signals in a time overlapping portion of subframe M-1 with adjusted subframe M when the subframe M-1 is an uplink subframe of a backhaul link comprises:
and the relay equipment prohibits the time overlapping part of the subframe M-1 and the adjusted subframe M from transmitting signals to the base station.
3. The method of claim 1, wherein the prohibiting transmission or reception of signals in a time overlapping portion of subframe M-1 with adjusted subframe M when the subframe M-1 is a downlink subframe of a backhaul link comprises:
and the relay equipment prohibits the time overlapping part of the subframe M-1 and the adjusted subframe M from receiving the signal transmitted by the base station.
4. The method of claim 1, wherein the prohibiting transmission or reception of signals in a time overlapping portion of subframe M-1 with adjusted subframe M when the subframe M-1 is an uplink subframe of an access link comprises:
and the relay equipment prohibits the time overlapping part of the subframe M-1 and the adjusted subframe M from receiving the signal transmitted by the terminal.
5. The method of claim 1, wherein the prohibiting the transmission or reception of signals in the subframe M-1 in a time overlapping portion with the adjusted subframe M when the subframe M-1 is a downlink subframe of an access link comprises:
and the relay equipment prohibits the time overlapping part of the subframe M-1 and the adjusted subframe M from transmitting signals to the terminal.
6. The method as claimed in any of claims 1-5, wherein the sending the signal required to be sent in the subframe to the terminal in the adjusted subframe M comprises:
sending a Physical Downlink Control Channel (PDCCH) signal to a terminal in the adjusted subframe M; or,
and sending a Physical Downlink Control Channel (PDCCH) signal and a service data signal to the terminal in the adjusted subframe M.
7. The method according to any of claims 1-5, wherein when subframe n + k is a downlink subframe, subframe M is subframe n + k; when the subframe n + k is not a downlink subframe, the subframe M is a first downlink subframe behind the subframe n + k;
and n is a subframe number of a subframe used by the base station for sending the timing adjustment command to the relay equipment, wherein the subframe number is a subframe number of a subframe used by the base station for sending the downlink subframe of the access link, and k is an integer not less than 0.
8. The method of claim 7, wherein k has a value of 6.
9. A relay device, characterized in that the device comprises:
a downlink timing adjustment unit, configured to adjust, in the subframe M, a downlink transmission timing from the relay device to the terminal;
an overlap determining unit for determining whether there is a time overlap portion between the subframe M-1 and the adjusted subframe M;
and the processing unit is used for forbidding the signal to be transmitted or received in the time overlapping part of the subframe M-1 and the adjusted subframe M when the overlapping determining unit determines that the time overlapping part exists between the subframe M-1 and the adjusted subframe M, and transmitting the signal which needs to be transmitted in the subframe to the terminal in the adjusted subframe M.
10. The relay device of claim 9, wherein the processing unit is to:
and when the subframe M-1 is an uplink subframe of a backhaul link, prohibiting a time overlapping part of the subframe M-1 and the adjusted subframe M from transmitting a signal to a base station.
11. The relay device of claim 9, wherein the processing unit is to:
and when the subframe M-1 is a downlink subframe of the backhaul link, prohibiting a time overlapping part of the subframe M-1 and the adjusted subframe M from receiving a signal sent by the base station.
12. The relay device of claim 9, wherein the processing unit is to:
and when the subframe M-1 is an uplink subframe of an access link, prohibiting a signal sent by a terminal from being received in a time overlapping part of the subframe M-1 and the adjusted subframe M.
13. The relay device of claim 9, wherein the processing unit is to:
and when the subframe M-1 is a downlink subframe of the access link, prohibiting a time overlapping part of the subframe M-1 and the adjusted subframe M from transmitting a signal to the terminal.
14. The relay device of any of claims 9-13, wherein the processing unit is to:
sending a Physical Downlink Control Channel (PDCCH) signal to a terminal in the adjusted subframe M; or,
and sending a Physical Downlink Control Channel (PDCCH) signal and a service data signal to the terminal in the adjusted subframe M.
15. The relay device according to any of claims 9-13, wherein when subframe n + k is a downlink subframe, subframe M is subframe n + k; when the subframe n + k is not a downlink subframe, the subframe M is a first downlink subframe behind the subframe n + k;
and n is a subframe number of a subframe used by the base station for sending the timing adjustment command to the relay equipment, wherein the subframe number is a subframe number of a subframe used by the base station for sending the downlink subframe of the access link, and k is an integer not less than 0.
16. The relay device of claim 15, wherein the value of k is 6.
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| CN 201010259804 CN102083135B (en) | 2010-08-20 | 2010-08-20 | Method and device for transmitting relay downlink data in long-term evolution advanced (LTE-A) system |
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| US10873920B2 (en) | 2017-10-09 | 2020-12-22 | Qualcomm Incorporated | Timing and frame structure in an integrated access backhaul (IAB) network |
| CN111200874B (en) * | 2018-11-20 | 2023-06-27 | 普天信息技术有限公司 | Channel configuration method and device based on D2D wireless frame structure |
| CN111447567B (en) * | 2020-03-25 | 2022-04-29 | 浙江大华技术股份有限公司 | Data broadcasting method and device, storage medium and electronic device |
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| CN101136681A (en) * | 2006-08-31 | 2008-03-05 | 富士通株式会社 | radio communication system |
| EP1931155A1 (en) * | 2005-09-30 | 2008-06-11 | Huawei Technologies Co., Ltd. | Wireless relay communication system and method |
| CN101415189A (en) * | 2007-10-16 | 2009-04-22 | 大唐移动通信设备有限公司 | Coexistent method for LTE TDD system and TD-SCDMA system |
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| EP1931155A1 (en) * | 2005-09-30 | 2008-06-11 | Huawei Technologies Co., Ltd. | Wireless relay communication system and method |
| CN101136681A (en) * | 2006-08-31 | 2008-03-05 | 富士通株式会社 | radio communication system |
| CN101415189A (en) * | 2007-10-16 | 2009-04-22 | 大唐移动通信设备有限公司 | Coexistent method for LTE TDD system and TD-SCDMA system |
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