CN101489254A - Signal sending method in long term evolution system - Google Patents

Abstract

A method for sending signals in a long-term evolution system, the method comprising: when a terminal needs to send a Physical Random Access Channel (PRACH) in an uplink subframe or an uplink pilot time slot, and in the subframe or an uplink pilot time slot, also When it is necessary to send other uplink channels and/or uplink signals, the terminal only sends PRACH in the subframe or uplink pilot slot. By adopting the method of the invention, the conflict problem between PRACH and other uplink physical channels or uplink signals can be solved. The method of the invention can ensure that when the terminal sends the scheduling request, it has the least impact on other uplink channels or signals of the system.

Description

A signal transmission method in long term evolution system

technical field

The present invention relates to the communication field, in particular to a signal transmission method in a Long Term Evolution (LTE for short) system.

Background technique

The frame structure of the LTE system TDD (Time Division Duplex, time division duplex) mode (also known as the second type of frame structure, namely frame structure type 2) is shown in Figure 1. In this frame structure, a radio frame of 10ms (307200Ts, 1ms=30720Ts) is divided into two half-frames, and each half-frame is 5ms long (153600Ts). Each half frame consists of 5 subframes with a length of 1 ms. The function of each subframe is shown in Table 1, wherein D represents a downlink subframe used to transmit downlink signals; U represents an uplink subframe used to transmit uplink signals. In addition, one uplink or downlink subframe is further divided into two 0.5ms time slots. S represents a special subframe, including three special time slots, namely DwPTS (Downlink Pilot Time Slot, downlink pilot time slot), GP (Guard Period, guard interval) and UpPTS (Uplink Pilot TimeSlot, uplink pilot time slot). In an actual system, the uplink and downlink configuration indexes will be notified to the mobile phone through a broadcast message.

Table 1

The frame structure of the FDD (Frequency Division Duplex, Frequency Division Duplex) mode of the LTE system (also known as the first type of frame structure, that is, frame structure type 1) is shown in Figure 2. A 10ms radio frame is divided into 20 time slots of 0.5ms, and two adjacent time slots form a subframe with a length of 1ms, that is, subframe i is composed of time slots 2i and 2i+1, where i=0, 1,...,9. In the FDD mode, all 10 subframes are used for the transmission of uplink or downlink signals, and the uplink and downlink are distinguished by different frequency bands.

The structure of the Physical Random Access Channel (PRACH for short, or random access opportunity, random access opportunity) of the LTE system is shown in FIG. 3 . The preamble is composed of CP and Sequence. Different preamble formats (preamble formats) mean different CP and/or Sequence lengths. The type of preamble format supported by the TDD mode of the LTE system is wrong! Reference source not found. shown.

leading format T _CP T _SEQ 0 3168 T _s 24576 T _s 1 21024 T _s 24576 T _s 2 6240 T _s 2·24576·T _s 3 21024 T _s 2·24576·T _s 4 448 T _s 4096 T _s

(only for type 2 frame structure)

Table 2

In the above preamble formats, preambleformat 0-3 are transmitted in normal uplink subframes, and preambleformat 4 is transmitted in UpPTS. in:

preamble format 0在一个普通上行子帧内传输；

preamble format 0 is transmitted in a normal uplink subframe;

preamble format 1、2在两个普通上行子帧内传输；

preamble format 1 and 2 are transmitted in two normal uplink subframes;

preamble format 3在三个普通上行子帧内传输；

preamble format 3 is transmitted in three normal uplink subframes;

preamble format 4在UpPTS内传输。

preamble format 4 is transmitted within UpPTS.

In the uplink non-synchronized state, the physical random access channel can be used for uplink synchronization. The main process includes 4 steps, namely:

101: The terminal (or UE, User Equipment) sends a random access preamble.

102: The base station (or eNB, E-UTRAN NodeB) detects after receiving the random access preamble, obtains the timing advance of the terminal, and sends the timing advance to the terminal through a random access response.

103: After receiving the timing advance, the terminal uses the PUSCH (Physical uplink shared channel) channel to send data information (called message 3, or message 3) to the base station, and the sent information may include "scheduling request information" .

104: After receiving the message 3, the base station sends a message 4 on a PDSCH (Physical downlink shared channel, physical downlink shared channel) to resolve the conflict.

In addition, in the uplink synchronization state, the terminal may also send scheduling request information through the above random access procedure.

The resource allocation in the LTE system is based on RB (Resource Block, resource block). One RB occupies 12 REs (Resource Element, resource element, one RE occupies one SC-FDMA symbol in the time domain) in the frequency domain, and one RE occupies one SC-FDMA symbol in the time domain. The RB occupies one time slot in the time domain, that is, one RB occupies 7 or 6 SC-FDMA (Single Carrier-Frequency Division Multiple Access, Single Carrier-Frequency Division Multiple Access) symbols in the time domain. That is to say, an RB occupies 7 SC-FDMA symbols under the condition of normal CP (Normal Cyclic Prefix, normal cyclic prefix), and occupies 6 SC-FDMA symbols under the condition of extended CP (Extended Cyclic Prefix, extended cyclic prefix). FDMA symbols.

，则RB的索引为0，1，......，

。FIG. 4 is a schematic diagram of the relationship between resource blocks and resource units in the prior art. As shown in FIG. 4, under the condition of a common CP, if the total number of RBs corresponding to the uplink system bandwidth is defined as

, then the index of RB is 0, 1, ...,

.

In the frequency domain, a PRACH channel occupies a bandwidth corresponding to 6 RBs, that is, 72 REs (ResourceElements), and the bandwidth of each RE is 15 kHz. The PRACH channels with the same position in the time domain are distinguished in the frequency domain.

In the frequency domain, common uplink subframes can transmit PRACH channel, Physical uplink shared channel (PUSCH for short), Physical uplink control channel (Physical uplink control channel, PUCCH for short), Sounding reference signal (Sounding reference signal, SRS for short) and other physical channels/signals. The SRS signal and the PRACH channel whose preamble format is 4 can be transmitted in the UpPTS.

As shown in Figure 5, the PUCCH channel format can be divided into two categories, a total of 6 types: the first category contains 3 formats, namely format 1, 1a, 1b, and the second category contains 3 formats, namely format 2, 2a, 2b. The first type of PUCCH is used to transmit SR (scheduling request, scheduling request) and ACK (Acknowledgment, confirmation response)/NACK (Negative Acknowledgment, negative response) signaling. Among them, format 1 is used to transmit SR, format 1a is used to transmit ACK/NACK of single code word stream, and format 1b is used to transmit ACK/NACK of dual code word stream. Multiple first-type PUCCHs (or called PUCCH resources) are multiplexed in one RB through code division. The second type of PUCCH is mainly used to transmit CQI (Channel Quality Indicator, channel quality indication), where format 2 only transmits CQI, format 2a is used to transmit CQI and ACK/NACK of a single codeword stream at the same time, and format2b is used to transmit CQI and ACK/NACK of dual codeword stream. Multiple second-type PUCCH channels are also multiplexed in one RB through code division.

In the uplink synchronization state, when the terminal needs to send a scheduling request through a random access procedure, the conflict between the PRACH and other uplink physical channels or uplink signals is an urgent problem to be solved.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a signal transmission method in the long-term evolution system, so as to solve the conflict between PRACH and other uplink physical channels or uplink signals when the terminal is in the uplink synchronization state question.

In order to solve the above problems, the present invention provides a signal transmission method in a long-term evolution system, the method comprising:

When the terminal needs to send the physical random access channel PRACH in the uplink subframe or the uplink pilot slot, and needs to send other uplink channels and/or uplink signals in the subframe or the uplink pilot slot, the terminal should Only PRACH is sent in a subframe or uplink pilot slot.

In addition, the other uplink channels include: Physical Uplink Control Channel PUCCH.

In addition, the content transmitted on the PUCCH is: acknowledgment ACK/negative acknowledgment NACK, and/or channel quality indicator CQI information.

In addition, the other uplink signals include: Sounding Reference Signal SRS.

The present invention also provides a method for sending signals in a long-term evolution system, the method comprising:

When the terminal needs to send PRACH in a subframe or uplink pilot slot, and also needs to send other uplink channels and/or uplink signals in the subframe or uplink pilot slot, the terminal according to the transmission of other uplink channels The type of content and/or uplink signal is selected to send only PRACH in the subframe or uplink pilot time slot, or send the other uplink channel and/or uplink signal in the subframe or uplink pilot time slot.

In addition, when the transmission content is ACK/NACK, the terminal sends the other uplink channel and/or uplink signal in the subframe.

In addition, when the transmission content is CQI, the terminal only sends PRACH in the subframe.

In addition, when the type of the uplink signal is SRS, the terminal only sends PRACH in the subframe.

By adopting the method of the invention, the conflict problem between PRACH and other uplink physical channels or uplink signals can be solved. The method of the invention can ensure that when the terminal sends the scheduling request, it has the least impact on other uplink channels or signals of the system.

Description of drawings

Fig. 1 shows the frame structure of LTE system TDD mode;

Fig. 2 shows the frame structure of LTE system FDD mode;

Figure 3 shows the PRACH channel structure;

Fig. 4 shows the structure of RB and RE;

FIG. 5 shows a schematic diagram of a PUCCH channel structure;

Fig. 6 is the schematic diagram of the first embodiment of the present invention;

Fig. 7 is the schematic diagram of the second embodiment of the present invention;

8 is a schematic diagram of a third embodiment of the present invention;

Fig. 9 is a schematic diagram of a fourth embodiment of the present invention.

Detailed ways

The core idea of the present invention is: when the terminal needs to send PRACH and other uplink channels or uplink signals at the same time, the terminal only sends PRACH (that is, sends random access preamble). The aforementioned simultaneous sending means: for a certain terminal, the time for sending PRACH and other physical uplink channels or signals overlaps, or in other words: sending PRACH and other physical uplink channels or uplink signals simultaneously in the same subframe or UpPTS.

In addition, the present invention also proposes the following technical solution: when the terminal needs to send PRACH and PUCCH at the same time, the terminal judges according to the condition, and if the condition is met, the terminal only sends PRACH, otherwise it sends PUCCH. The above conditions include that if the CQI is sent on the PUCCH, the terminal only sends the PRACH, and if the ACK/NACK is sent on the PUCCH, the terminal only sends the PUCCH. The aforementioned simultaneous sending means: for a certain terminal, the time for sending PRACH and PUCCH channels overlaps, or in other words: sending PRACH and PUCCH channels simultaneously in the same subframe or UpPTS.

The above method can be applied when the base station does not allocate PUCCH resources for sending SR (scheduling request) to the terminal, and the terminal sends a scheduling request through a random access procedure.

In addition, the above-mentioned PRACH may also be called a random access preamble or a random access opportunity.

The present invention will be described in detail below with reference to the drawings and embodiments.

First embodiment:

In this embodiment, the terminal uses preamble format 4 in TDD mode.

In a certain wireless frame, the terminal needs to send SRS on the UpPTS, and at the same time, the terminal also needs to send the physical random access channel (preamble) of the preamble format 4; at this time, the terminal only sends the PRACH on the UpPTS, and gives up sending the SRS (as shown in the figure 6).

Second embodiment:

In this embodiment, in TDD or FDD mode, the terminal uses preamble format 0.

On a certain uplink subframe of a certain radio frame, the terminal needs to send SRS and/or send ACK/NACK through PUCCH, and at the same time, the terminal also needs to send PRACH; at this time, the terminal only sends PUCCH and/or SRS in the uplink subframe , and send the PRACH in subsequent subframes (as shown in FIG. 7 ).

Third embodiment:

In this embodiment, the terminal uses preamble format 1 or 2 in TDD or FDD mode.

On a certain uplink subframe of a certain wireless frame, the terminal needs to send CQI through the PUCCH, and the terminal also needs to send the PRACH; at this time, the terminal only sends the PRACH in the uplink subframe, and gives up sending the PUCCH (as shown in Figure 8) .

Fourth embodiment:

In this embodiment, the terminal uses preamble format 3 in TDD or FDD mode.

On a certain uplink subframe of a certain radio frame, the terminal needs to send SRS, and at the same time, the terminal also needs to send PRACH; at this time, the terminal only sends PRACH in the uplink subframe, and gives up sending SRS (as shown in FIG. 9 ).

Claims (8)

1. A signaling method in a long-term evolution system, characterized in that the method comprises: When the terminal needs to send the physical random access channel PRACH in the uplink subframe or the uplink pilot slot, and needs to send other uplink channels and/or uplink signals in the subframe or the uplink pilot slot, the terminal should Only PRACH is sent in a subframe or uplink pilot slot. 2. The method of claim 1, wherein: The other uplink channels include: Physical Uplink Control Channel PUCCH. 3. The method of claim 1, wherein: The content transmitted on the PUCCH is: acknowledgment ACK/negative acknowledgment NACK, and/or channel quality indicator CQI information. 4. The method of claim 1, wherein: The other uplink signals include: Sounding Reference Signal SRS. 5. A signal transmission method in a long-term evolution system, characterized in that the method comprises: When the terminal needs to send PRACH in a subframe or uplink pilot slot, and also needs to send other uplink channels and/or uplink signals in the subframe or uplink pilot slot, the terminal according to the transmission of other uplink channels The type of content and/or uplink signal is selected to send only PRACH in the subframe or uplink pilot time slot, or send the other uplink channel and/or uplink signal in the subframe or uplink pilot time slot. 6. The method of claim 5, wherein: When the transmission content is ACK/NACK, the terminal sends the other uplink channel and/or uplink signal in the subframe. 7. The method of claim 5, wherein: When the transmission content is CQI, the terminal only sends PRACH in the subframe. 8. The method of claim 5, wherein: When the type of the uplink signal is SRS, the terminal only sends PRACH in the subframe.

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