CN101162987A - A transmission method of pilot signal in uplink special time slot of time division duplex system - Google Patents

Abstract

A method for sending a pilot signal in a time division duplex system uplink special time slot, which is applied to the LTE system TDD model, comprising the following steps: a terminal sends a random access channel, uplink data and one or more pilot signals, wherein, the terminal sends a pilot signal on the last OFDM symbol; when the pilot signal on the last OFDM symbol is a data demodulation pilot, if the channel measurement pilot is also sent, then in other symbols When the pilot signal on the last OFDM symbol is a channel measurement pilot, if the channel measurement pilot is not used for data demodulation, the data demodulation pilot is sent on the penultimate symbol; different pilots Signals are not on the same symbol. Adopting the pilot transmission method of the present invention can well guarantee the performance of the uplink pilot time slot, and can also be well compatible with other uplink pilot transmission methods.

Description

A transmission method of pilot signal in uplink special time slot of time division duplex system

technical field

The invention relates to the field of mobile communication, in particular to a method for sending a pilot signal in a time division duplex system uplink special time slot.

Background technique

The frame structure of the TDD (Time Division Duplex) model of the current LTE (Long Term Evolution) system is shown in FIG. 1 . In this frame structure, a 10ms radio frame is divided into two half-frames, each half-frame includes 10 time slots (numbered from 0 to 9) with a length of 0.5ms, and each two time slots form a length It is a subframe of 1 ms, and one half frame includes 5 subframes (numbered from 0 to 4). For the short cyclic prefix (Cyclic Prefix, CP) with a length of 5.21us and 4.69us, a time slot contains 7 uplink/downlink symbols with a length of 66.7us, of which the CP length of the first symbol is 5.21us, and the remaining 6 The CP length of a symbol is 4.69us; for a long CP with a length of 16.67us, a time slot contains 6 uplink/downlink symbols. In addition, in this frame structure, the configuration characteristics of the subframe are:

(1) Subframe #0 is fixed for downlink transmission;

(2) Subframe #1 is a special subframe, which contains 3 special time slots, namely the downlink special time slot DwPTS (Downlink Pilot Time Slot), the guard interval GP (Guard Period) and the uplink special time slot UpPTS (Uplink Pilot Time Slot). Time Slot). in:

(21) DwPTS is used for downlink transmission, in which at least one downlink OFDM (Orthogonal Frequency Division Multiplexing) symbol is used to transmit the primary synchronization signal P-SCH (Primary-Synchronization CHannel), when the DwPTS contains multiple OFDM symbols, P -SCH is placed on the first OFDM symbol (as shown in Figure 1);

(22) GP is a protection time and does not transmit any data;

(23) UpPTS is used for uplink transmission, which contains at least 2 uplink SC-FDMA (single carrier frequency division multiplexing) symbols for transmission of physical random access channel PRACH (Physical Random Access CHannel). When the number of symbols included in the UpPTS is greater than 2, the PRACH is transmitted on the first two symbols (as shown in FIG. 1 ).

In the frame structure, in order to coexist with the TD-SCDMA (Time Division Synchronous Code Division Multiple Access) system, the number of OFDM symbols contained in the uplink special time slot UpPTS is variable, and at least two uplink SC-FDMA symbols are used for The PRACH is transmitted, which makes the structure of the uplink special time slot inconsistent with that of other general uplink time slots.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for sending pilot signals in uplink special time slots of a time division duplex system.

The technical scheme adopted in the present invention is:

A method for sending a pilot in a time division duplex system uplink special time slot, applied in the LTE system TDD model, comprising the following steps:

The terminal sends a random access channel, uplink data and one or more pilot signals on an uplink special time slot, wherein the terminal sends the pilot signal on the last OFDM symbol; when the last OFDM symbol on When the pilot signal is a data demodulation pilot, if the channel measurement pilot is to be sent, it is sent on other symbols; when the pilot signal on the last OFDM symbol is a channel measurement pilot, if the channel measurement pilot If the frequency is not used for data demodulation, the data demodulation pilot is sent on the penultimate symbol; different pilot signals are not on the same symbol.

Further, the terminal also sends the second data demodulation pilot on any other symbol of the uplink special time slot.

Further, when the number of symbols contained in the uplink special time slot is less than or equal to m, the terminal does not send the second data demodulation pilot; otherwise, the terminal sends the second data demodulation pilot on the uplink special time slot The second data demodulation pilot, where m=4, 5, 6.

Further, when the number of symbols contained in the uplink special time slot is greater than m, the terminal sends the second data demodulation pilot on the third symbol of the uplink special time slot, where m= 4, 5, 6.

Further, when the number of symbols contained in the uplink special time slot is greater than m and an extended cyclic prefix is used, the terminal sends the second data demodulation pilot on the penultimate m-th symbol of the uplink special time slot , where m=5,6.

Further, when the number of symbols contained in the uplink special time slot is greater than m and a conventional cyclic prefix is used, the terminal sends the second data demodulation on the penultimate (m+1)th symbol of the uplink special time slot pilot, where m=5,6.

Adopting the pilot transmission method of the present invention can well guarantee the performance of the uplink pilot time slot, and can also be well compatible with other uplink pilot transmission methods.

Description of drawings

FIG. 1 is a schematic diagram of a frame structure of a TDD system in the prior art;

FIG. 2 is a schematic diagram of a position of a pilot in an uplink pilot time slot in an embodiment;

FIG. 3 is a schematic diagram of a position of a pilot in another uplink pilot time slot in an embodiment;

Fig. 4 is a schematic diagram of another pilot position in an uplink pilot time slot in an embodiment.

Detailed ways

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

A method for sending a pilot signal in a time division duplex system uplink special time slot, which is applied to the LTE system TDD model, comprising the following steps: a terminal sends a random access channel, uplink data and one or more pilot signals, wherein, the terminal sends a pilot signal on the last OFDM symbol; when the pilot signal on the last OFDM symbol is a data demodulation pilot, if the channel measurement pilot is to be sent, then in other symbols When the pilot signal on the last OFDM symbol is a channel measurement pilot, if the channel measurement pilot is not used for data demodulation, the data demodulation pilot is sent on the penultimate symbol; different pilots Signals are not on the same symbol. The terminal also sends the second data demodulation pilot on any other symbol of the uplink special time slot or when the number of symbols contained in the uplink special time slot is less than or equal to m, the terminal does not send the second data demodulation pilot; otherwise, The terminal sends the second data demodulation pilot on the uplink special time slot. The sending method includes the following three methods:

The first way: when the number of symbols contained in the uplink special time slot is greater than m, the terminal sends the second data demodulation pilot on the third symbol of the uplink special time slot, where m= 4, 5, 6.

The second method: when the number of symbols contained in the uplink special time slot is greater than m and an extended cyclic prefix is used, the terminal sends the second data demodulation on the penultimate m-th symbol of the uplink special time slot pilot, where m=5,6.

The third method: when the number of symbols contained in the uplink special time slot is greater than m and a conventional cyclic prefix is used, the terminal sends the second data on the penultimate (m+1)th symbol of the uplink special time slot demodulation pilot, where m=5,6.

For the above frame structure, the terminal sends a pilot on the last OFDM symbol of the uplink special time slot, which can be a data demodulation pilot or a sounding (channel measurement) pilot; and, when the uplink is special When the number of symbols contained in the slot is more than 2, another data demodulation pilot can be sent, which can be sent on fixed symbols in the uplink special time slot, for example, when the number of symbols contained in the uplink special time slot When it is less than or equal to 5, the second data demodulation pilot is not sent, and when the number of symbols contained in the uplink special time slot is greater than 5, the second data demodulation pilot is fixedly sent on the third symbol; the second data demodulation The modulation pilot can also be changed according to the number of symbols contained in the uplink special time slot. For example, when the number of symbols contained in the uplink special time slot is less than 5, the second data demodulation pilot is not sent. When the uplink special time slot When the number of symbols contained in is greater than 5, the regular cyclic prefix is sent on the sixth last symbol, and the extended cyclic prefix is sent on the fifth last symbol.

Alternatively, the data demodulation pilot in the uplink special time slot can also be sent on the penultimate OFDM symbol, the sounding pilot can be sent on the last OFDM symbol, or the sounding pilot can not be sent, and the second data demodulation The pilot can be sent on fixed symbols in the uplink special time slot. For example, when the number of symbols contained in the uplink special time slot is less than 6, the second data demodulation pilot is not sent. When the uplink special time slot contains When the number of symbols is greater than 6, the second data demodulation pilot is fixedly sent on the third symbol; the second data demodulation pilot can also be changed according to the number of symbols contained in the uplink special time slot, for example: when the uplink When the number of symbols contained in the special time slot is less than 6, the second data demodulation pilot is not sent. When the number of symbols contained in the uplink special time slot is greater than 6, in the regular cyclic prefix, the penultimate symbol is sent , sent on the sixth-to-last symbol when extending the cyclic prefix.

An application example of the present invention will be further described below.

Figure 2 is a schematic diagram of the position of the pilot in the uplink special time slot in a frame structure. Among them, k is the serial number of each symbol. In this schematic diagram, the position of the pilot in 12 consecutive subcarriers is described, where the number of OFDM symbols contained in the uplink special time slot is 11, and the data demodulation pilot or sounding pilot is fixed on the last OFDM symbol For sending, the second data demodulation pilot is fixedly sent on the penultimate sixth OFDM symbol.

Figure 3 is a schematic diagram of the position of the pilot in the uplink special time slot in another frame structure. Among them, k is the serial number of each symbol. In this schematic diagram, the positions of the pilots in 12 consecutive subcarriers are described, wherein the number of OFDM symbols contained in the uplink special time slot is 11, and the data demodulation pilots are sent on the penultimate OFDM symbol. The second data demodulation pilot is fixedly sent on the penultimate seventh OFDM symbol.

Figure 4 is a schematic diagram of the position of the pilot in the uplink special time slot in another frame structure. Among them, k is the serial number of each symbol. In this schematic diagram, the positions of the pilots in 12 consecutive subcarriers are described, where the number of OFDM symbols contained in the uplink special time slot is 10, and the data demodulation pilot or sounding pilot is fixed at the penultimate OFDM The second data demodulation pilot is always sent on the penultimate sixth OFDM symbol.

It should be noted that the frequency domain position of the pilot is consistent with the frequency domain position of the corresponding data. The pilots of each user are multiplexed by frequency division. When the user has multiple antennas, the pilots of each antenna are multiplexed by code division. .

Of course, the present invention can also have other various embodiments, and those skilled in the art can make various corresponding changes and deformations according to the present invention without departing from the spirit and essence of the present invention, but these corresponding Changes and deformations should belong to the scope of protection of the appended claims of the present invention.

Claims (6)

1. the sending method of pilot signal in the tdd systems uplink special time slot is applied to it is characterized in that in the LTE system TDD model, may further comprise the steps:

Terminal sends Random Access Channel, upstream data and one or more pilot signal on a uplink special time slot, wherein, described terminal is pilot signal transmitted on OFDM symbol in the end; When the pilot signal on described last OFDM symbol is the data demodulates pilot tone,, then on other symbols, send if also want the transmitting channel measurement pilot frequency; When the pilot signal on described last OFDM symbol is channel measurement pilot frequency,, then on the penult symbol, send described data demodulates pilot tone if channel measurement pilot frequency need not be done the data demodulation; Different pilot signals is not on same symbol.

2. the method for claim 1 is characterized in that,

Described terminal also sends the described second data demodulates pilot tone on other any one symbol of described uplink special time slot.

3. the method for claim 1 is characterized in that,

When the symbolic number that comprises in the described uplink special time slot during smaller or equal to m, described terminal does not send the described second data demodulates pilot tone; Otherwise described terminal sends described second data demodulation pilot frequency on described uplink special time slot, wherein, and m=4,5,6.

4. the method for stating as claim 3 is characterized in that,

When the symbolic number that comprises in the described uplink special time slot during greater than m, described terminal sends the described second data demodulates pilot tone on the 3rd symbol of described uplink special time slot, wherein, and m=4,5,6.

5. the method for stating as claim 3 is characterized in that,

The symbolic number that comprises in the described uplink special time slot is greater than m and when adopting extended cyclic prefix, and described terminal sends the described second data demodulates pilot tone on m symbol of inverse of described uplink special time slot, wherein, and m=5,6.

6. the method for stating as claim 3 is characterized in that,

The symbolic number that comprises in the described uplink special time slot is greater than m and when adopting the regular circulation prefix, and described terminal sends the described second data demodulates pilot tone on m+1 symbol of inverse of described uplink special time slot, wherein, and m=5,6.

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