CN103546413A - Carrier scheme applicable to 3.5GHz TDD (time division duplexing) frequency bands - Google Patents

Abstract

The invention relates to a carrier scheme applicable to 3.5GHz TDD (time division duplexing) frequency bands. The carrier scheme includes that broadcast channels are demodulated by pilot-frequency DM RS (demodulation reference signals), PSS/SSS (primary synchronization signals/secondary synchronization signals) in FDD (frequency division duplexing) frame structures are shifted to third OFDM (orthogonal frequency division multiplexing) symbols and seventh OFDM symbols when the PSS/SSS are collided with the DM RS and CSI-RS (channel state indication-reference signals), each PSS in each TDD frame structure is shifted to a zeroth OFDM symbol, and each SSS in the each TDD frame structure is shifted to an eighth OFDM symbol of a prior subframe. The carrier scheme has the advantages that a plurality of technologies for improving the spectral efficiency can be introduced owing to carriers, CRS (common reference signals) and PDCCH (physical downlink control channels) are not transmitted on the carriers, the carrier scheme is favorable for saving energy and eliminating inter-cell interference, and the independent work characteristic of the 3.5GHz TDD frequency bands can be guaranteed.

Description

A kind of carrier schemes that can be used for 3.5GHz TDD frequency range

Technical field

The present invention relates to wireless communication field, particularly, relate to a kind of carrier schemes of the 3.5GHz of can be used for TDD frequency range.

Background technology

Along with extensively popularizing of intelligent terminal, increasing wireless data service occurs in indoor, and the feature of indoor business is Hypomobility, high traffic.In order to meet the demand of following wireless access volume of business, requiring has larger bandwidth, more spectral efficient and more intensive network design, and wherein large bandwidth more easily appears at high band.A lot of countries are for TDD(time division duplex in the frequency range of 3.5GHz at present, Time Division Duplexing) pattern, and that the technology of tdd mode is more suitable for being applied to is relatively indoor, therefore consider to introduce the small-cell of frequency range of 3.5GHz for improving the capacity of indoor business and optimizing indoor covering.

If directly introduce TD-LTE(timesharing Long Term Evolution in this frequency range, Time Division Long Term Evolution) technology, new frequency range can be divided into the frequency range of several backward compatibilities, then the method for the random access of proportion is carried out the access point of micro cell deployment, can access the terminal of LTER8-R10 so on the one hand, guarantee backwards compatibility, can configure or increase new transmission mode by high level on the other hand, realization is for the enhancing of the later terminal technology of LTE R11, to guarantee that the carrier wave of this frequency range is the TDD carrier wave of backward compatibility.The problem of this scheme is the technology of the raising spectrum efficiency that more difficult introducing is new, because look for novelty, frequency range is LTE backward compatibility, cell-specific pilot tone CRS(core router) and the expense of control channel PDCCH too large, under the scene of disposing in the large density of heterogeneous network, easily bring interference, waste power.

Summary of the invention

In order to address the above problem, the present invention proposes a kind of carrier schemes of the 3.5GHz of can be used for TDD frequency range.

A carrier schemes that can be used for 3.5GHz TDD frequency range, is used demodulation pilot frequency DM RS(demodulated reference signal) demodulation broadcast channel.

Further, when synchronizing signal PSS/SSS and DM RS and CSI-RS(channel state information reference signals) pilot tone when collision, PSS/SSS in FDD frame structure moves on to the 3rd OFDM(OFDM) on symbol and the 7th OFDM symbol, PSS in tdd frame structure is displaced on the 0th OFDM symbol, and SSS is displaced on the 8th OFDM symbol of last subframe.

Further, the information that described broadcast channel sends is community shared information.

Further, transmit diversity is 8 antennas.

This carrier wave can work alone in 3.5GHz TDD frequency range, for optimizing indoor wireless networks.One aspect of the present invention can guarantee that 3.5GHz TDD carrier wave works alone, and can make full use of again on the other hand the advantage of this carrier wave, introduces the more technology that improves spectrum efficiency.

Accompanying drawing explanation

Fig. 1 is the LTE downlink synchronous signal schematic diagram of FDD frame structure;

Fig. 2 is the LTE downlink synchronous signal schematic diagram of tdd frame structure.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that embodiment described herein is only for explaining the present invention, rather than for limiting the present invention.

This patent proposes to carry out demodulation broadcast channel with demodulation pilot frequency DM RS, because DM RS is UE special use, and the information that broadcast channel sends is community shared information, therefore DM RS does not make the pre-encode operation of UE editing machine special use, to guarantee that each UE all can correctly receive broadcast channel PBCH(Physical Broadcast Channel).In addition, when being only 4 at most for transmitting antenna in LTE, the transmission diversity scheme of broadcast channel is defined.Here this emission diversity scheme is expanded to 8 antennas.

$\left[\begin{array}{cccccccc}{S}_1& -S_2^{*}& & & & & & \\ S_2& S_1^{*}& & & & & & \\ & & S_3& -S_4^{*}& & & & \\ & & S_4& S_3^{*}& & & & \\ & & & & S_5& -S_5^{*}& & \\ & & & & S_6& S_6^{*}& & \\ & & & & & & S_7& -S_8^{*}\\ & & & & & & S_8& S_8^{*}\end{array}\right]$

Synchronizing signal PSS/.SSS is in FDD frame structure, primary and secondary synchronization signals PSS/SSS signal is positioned on the OFDM symbol 5,6 of the 0th subframe and the 5th subframe, in tdd frame structure, master sync signal is positioned at above the OFDM symbol 2 of the 1st subframe and the 6th subframe, and auxiliary synchronous signals is positioned at above the OFDM symbol 13 of the 0th subframe and the 5th subframe.For fear of colliding with other pilot tones, as shown in Figure 1, the PSS/SSS in FDD frame structure is moved on on the 3rd OFDM symbol and the 7th OFDM symbol; As shown in Figure 2, the PSS in tdd frame structure is displaced on the 0th OFDM symbol, and SSS is displaced on the 8th OFDM symbol of last subframe.

TDD is different with the PSS/SSS position in FDD frame structure, and in the process that is conducive to detect in terminal, identification is TDD system or FDD system.Adopt the data demodulates that does not affect in this way DM RS, but require the reposition of terminal blind Detecting PSS/SSS on new carrier wave.

By introducing above-mentioned carrier wave, can introduce the technology of more raising spectrum efficiency, be exactly not send CRS and PDCCH on new carrier type the most intuitively, be conducive to the saving of energy and the elimination of presence of intercell interference, and guaranteed the characteristic that 3.5GHz TDD frequency range works alone.In introducing described carrier wave process, the problem of the broadcast channel demodulation bringing and major-minor pilot tone and the collision of other pilot tones, has all provided corresponding solution.

Above are only preferred embodiment of the present invention, certainly, can also have other execution mode with further exploration according to actual needs.But, should be clear and definite, the conversion based on the similar execution mode with same idea above-mentioned or that other is not explained out, within all should being encompassed in the protection range of the claims in the present invention.

Claims (4)

1. a carrier schemes that can be used for 3.5GHz TDD frequency range, is characterized in that, uses demodulation pilot frequency DM RS demodulation broadcast channel.

2. carrier schemes according to claim 1, it is characterized in that, when synchronizing signal PSS/.SSS and DM RS and the collision of CSI-RS pilot tone, PSS/SSS in FDD frame structure moves on on the 3rd OFDM symbol and the 7th OFDM symbol, PSS in tdd frame structure is displaced on the 0th OFDM symbol, and SSS is displaced on the 8th OFDM symbol of last subframe.

3. carrier schemes according to claim 1, is characterized in that, the information that described broadcast channel sends is community shared information.

4. carrier schemes according to claim 1, is characterized in that, transmit diversity is 8 antennas.

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