CN101635619B - Method, base station and system for transmitting subcarriers - Google Patents

Abstract

The embodiment of the invention provides a method, a base station and a system for transmitting subcarriers. The method comprises the steps: dividing a plurality of subcarriers of signals to be transmitted on the entire frequency band into a plurality of transmission groups; distributing the subcarriers of the signals to be transmitted on the entire frequency band to at least two transmission antennas of the base station and broadcasting and transmitting the signals. The method and the system for transmitting subcarriers can enhance the average power of each subcarrier for transmitting the same OFDM signal by a plurality of transmission antennae under the condition that each antenna transmits partial data by synchronous/broadcasting/controlling channels formed by omnibearing wave beams, thereby increasing the coverage range of downlink channels of the base station, raising the signal-to-noise ratio for the reception of user equipment, ensuring the reliable decoding of information transmitted by the user equipment to the base station, enlarging district edge coverage and increasing the throughput.

Description

Subcarrier transmission method, base station and system

technical field

The embodiments of the present invention relate to the technical field of wireless communication, and in particular, to a subcarrier transmission method, base station and system.

Background technique

In the 802.16e Orthogonal Frequency Division Multiple Access (OFDMA) frame structure mode, the first three "OFDM symbols" in the downlink information frame of the base station need to be broadcast to all user equipment, so The first three "OFDMsymbols" mentioned above include the synchronization signal (Preamble) signal (accounting for one OFDM symbol), the frame control header (Frame Control Header; hereinafter referred to as: FCH) and DL_MAP (accounting for two OFDMsymbols).

Among them, the "Preamble" signal information is used for user equipment to synchronize, obtain cell ID (CellID) information, receive signal strength indicator (Receive Signal Strength Indicator; hereinafter referred to as: RSSI), carrier-to-interference-noise ratio (Carrier-to-interference-and -noise ratio; hereinafter referred to as: CINR) measurement, etc.; DL_MAP signal information includes the configuration information of each subband (burst) in the downlink frame and part of the control signaling, and its encoding method is determined by the FCH.

It can be seen that the user equipment needs to reliably decode the information, so as to ensure correct decoding of the subsequent "burst". In order to ensure that these information can be reliably received by the user equipment, the agreement stipulates that the "Preamble" signal adopts the boosted binary phase shift keying (Boosted Binary Phase Shift Keying; hereinafter referred to as: Boosted BPSK) modulation method, and the DL_MAP signal and the FCH signal adopt Quadrature Phase Shift Keying (Quadrature Phase Shift Keying; hereinafter referred to as: QPSK) modulation method.

In the process of realizing the present invention, the inventors found that there are at least the following problems in the prior art: although the above-mentioned three signals are modulated with high robustness to improve the success rate of information reception in the prior art, the 802.16e OFDMA In the frame structure mode, when the base station transmits the first three "OFDMsymbol" signals of the downlink information frame, due to the limited level of the power amplifier device at the radio frequency end, the user equipment receives a low signal-to-noise ratio and cannot guarantee the reliability of the information. decoding.

Contents of the invention

Embodiments of the present invention provide a subcarrier transmission method, base station and system, which are used to solve the defect that user equipment cannot reliably receive information in the prior art, and can ensure reliable reception of information.

An embodiment of the present invention provides a subcarrier sending method, including:

Divide the several subcarriers of the signal to be transmitted in the entire frequency band into several transmission groups, and assign the several subcarriers of the signal to be transmitted in the entire frequency band to the M transmitting antennas of the base station for broadcast transmission in units of the transmission groups , where M≥2.

An embodiment of the present invention provides a base station, including:

An allocation processing module, configured to divide several subcarriers of the signal to be transmitted in the entire frequency band into several transmission groups, and use the transmission group as a unit to allocate the several subcarriers of the signal to be transmitted in the entire frequency band to the base station M transmitting antennas, where M≥2;

The transmitting antenna is used for broadcasting and sending the subcarriers allocated by the allocation processing module.

An embodiment of the present invention further provides a subcarrier transmission system, including the base station provided in the above embodiments and user equipment configured to receive the subcarriers broadcast and transmitted by the base station.

The sub-carrier transmission method, base station and system provided by the embodiments of the present invention can increase the average power of each sub-carrier, thereby increasing the The downlink channel coverage of the base station and the improvement of the user equipment receiving signal-to-noise ratio ensure that the user equipment can reliably decode the information sent by the base station, increase cell edge coverage, and improve throughput.

Description of drawings

FIG. 1 is a schematic diagram of a simulation of bit error rate performance of user equipment in an embodiment of the present invention;

FIG. 2 is a schematic diagram of a simulation of user equipment bit error rate performance in another embodiment of the present invention;

FIG. 3 is a flow chart of Embodiment 1 of the subcarrier sending method of the present invention;

FIG. 4 is a transmission principle diagram of Embodiment 1 of the subcarrier transmission method of the present invention;

FIG. 5 is a flow chart of Embodiment 2 of the subcarrier sending method of the present invention;

6 is a schematic diagram of a multi-antenna subcarrier allocation scheme in Embodiment 2 of the subcarrier transmission method of the present invention;

FIG. 7 is a schematic diagram of antenna switching in an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a base station according to an embodiment of the present invention.

Detailed ways

The technical solutions of the embodiments of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. In the 802.16e OFDMA frame structure mode, since the base station adopts a single-antenna broadcast transmission method with low power for the signal that needs to be broadcasted, the signal-to-noise ratio received by the user equipment is low, and the reliable decoding of the information cannot be guaranteed. Phenomenon. In order to avoid the defects of the existing technology, increase the coverage of the base station, and improve the receiving signal-to-noise ratio of the user equipment, the embodiment of the present invention provides a multi-antenna omnidirectional beamforming scheme, that is, several subcarriers of the signal to be transmitted on the entire frequency band Divide into several transmission groups, and use the transmission group as a unit to allocate several subcarriers of the signal to be transmitted in the entire frequency band to M transmission antennas of the base station for broadcast transmission, where M≥2. The purpose of the embodiments of the present invention is to use multiple antennas to form omnidirectional beams, and to ensure reliable reception of user equipment by increasing the average transmit power of subcarriers. The embodiment of the present invention takes the 802.16e OFDMA frame structure as an example for illustration, but is not limited to the transmission of this frame structure.

First, the following concepts are introduced: OFDM system is a multi-carrier system, such as 1024 sub-carriers-10MHz bandwidth, or 2048 sub-carriers-20MHz bandwidth, etc., and the transmission signal is modulated on multiple carriers. Signal: In this embodiment of the present invention, it refers to all subcarriers in the frequency domain of one OFDM symbol, for example, 1024 subcarriers. Part of the frequency domain data refers to part of the subcarriers in the frequency domain of an OFDM symbol, for example, only a part of the 1024 subcarriers. A subcarrier is the smallest unit of an OFDM symbol. For example, when the bandwidth is 10MHz, 1024 subcarriers in the frequency domain constitute an OFDM symbol.

The following firstly introduces the principle of multi-antennas forming omni-directional beams to increase the average transmit power of subcarriers.

Assuming that there are N _t subcarriers to be transmitted in the entire frequency band of the signal to be transmitted, and the maximum transmission power of a single antenna is P _t due to the limited level of power amplifier devices at the radio frequency end, when the base station uses a single antenna for broadcast transmission, the average distribution of The transmit power of subcarriers is P _t /N _t . If the base station uses M (M≥2) antennas to broadcast and transmit the signal, the N _t subcarriers on each "OFDM symbol" signal are divided into M groups according to the arrangement in the frequency domain, and each transmitting antenna is responsible for Send one of them, then for any one transmit antenna, the transmit power allocated to each subcarrier on average is P _t /(N _t /M)=M*P _t /N _t , it can be known that the transmit power allocated to each The transmitting power of the subcarriers is increased by M times, so that after the combination at the receiving end, the total receiving power of the user equipment will increase to M times that when the original base station transmits with a single antenna.

According to the Friis (FRIIS) transmission formula, the base station uses M antennas for omnidirectional broadcast transmission, which can increase the coverage distance , while the user equipment receiving signal-to-noise ratio is increased by M times compared with the base station using a single antenna for broadcast transmission, that is, 10log M dB, so that the bit error rate performance is improved by 10log M dB.

For details, please refer to Figure 1 and Figure 2. Figure 1 is a schematic diagram of the simulation of the bit error rate performance of the user equipment in an embodiment of the present invention, and Figure 2 is a schematic diagram of the simulation of the bit error rate performance of the user equipment in another embodiment of the present invention, wherein Figure 1 shows Figure 2 shows the BER performance simulation results when the user equipment speed is 30km/h and the distance between the transmitting antennas is 0.5λ. In Figures 1 and 2, "*" indicates single-antenna transmission, "△" indicates two-antenna transmission, and "□" indicates four-antenna transmission, where the abscissa indicates Signal to Noise Ratio (Signal to NoiseRatio; hereinafter referred to as: SNR) , and the ordinate represents the bit error rate (Bit Error Rate; BER for short), as can be seen from Figure 1 and Figure 2, the bit error rate performance of signal information transmitted by multi-antenna omnidirectional beam broadcasting has been significantly improved. In addition, the high peak-to-average ratio is also one of the main disadvantages of the OFDM system, that is, compared with the single-carrier system, the instantaneous value of the output signal of the OFDM transmitter will fluctuate greatly, which will require the power amplifier inside the system, Components such as A/D converters and D/A converters have a large linear dynamic range. Conversely, the nonlinearity of these components will also cause nonlinear distortion to signals with a large dynamic range, and the generated harmonics will cause mutual interference between sub-channels, thereby affecting the performance of the OFDM system. According to the analysis, for an OFDM system with N subcarriers, the peak-to-average power ratio (PAPR) is 10log ₁₀ NdB. Taking N=1024 as an example, the PAPR is 30dB at this time. Of course, this is a very extreme In general, the PAPR in the OFDM system will not reach this value. When using the omnidirectional broadcast beamforming algorithm proposed in the embodiment of the present invention, the number of subcarriers allocated to each transmit antenna is N/M, so for each transmit antenna, the PAPR at this time is 10log ₁₀ (N /M)=10log ₁₀ N-10log ₁₀ M dB, it can be seen that, for "Preamble", FCH and DL_MAP signals, the omnidirectional beamforming method provided by the embodiment of the present invention can reduce to a certain extent the PAPR value, the reduction is 10log ₁₀ M dB.

According to the above correlation analysis, when the base station uses two antennas for transmission, since the power of each subcarrier increases to twice the subcarrier power of the single-antenna transmission, the transmission power of each sub-carrier of the user equipment is twice that of the single-antenna transmission. , so that the bit error rate performance has a 3dB improvement. Similarly, when the base station uses 4 antennas to transmit, the power of each subcarrier at the receiving end is 4 times that of a single antenna, which improves the bit error rate performance by 6dB.

Figure 3 is a flow chart of Embodiment 1 of the subcarrier transmission method of the present invention, and Figure 4 is a schematic diagram of the transmission principle of Embodiment 1 of the subcarrier transmission method of the present invention, as shown in Figure 3 and Figure 4, the multi-antenna omnidirectional The beamforming method is described by taking the "Preamble" signal in the OFDMA frame structure sent by the base station in the Worldwide Interoperability for Microwave Access (WiMAX) system as an example, including:

Step 100, evenly divide several subcarriers of the signal to be transmitted evenly distributed on the entire frequency band into M transmission groups in order, and send the subcarriers included in each transmission group to the M transmission antennas corresponding to the transmission group transmitting antenna;

Assuming that the base station uses M transmitting antennas to broadcast and transmit the signal to be sent, such as the "Preamble" signal, due to the particularity of the "Preamble" signal, it does not belong to any permutation domain, and the "Preamble" signal is evenly distributed over the entire frequency band on the physical frame , so the N _t subcarriers of the "Preamble" signal in the entire frequency domain can be evenly and sequentially divided into M segments to form M sending groups, and each transmitting antenna of the base station is responsible for sending one of the sending groups.

Specifically, because the "Preamble" data is a pseudo-random sequence determined by the segment (segment) number and the cell ID (CELL ID) given by the protocol, that is, each pair of CELL ID and "segment" corresponds to a set of pseudo-random sequence codes (Pseudo-random -Noise; hereinafter referred to as: PN code), the PN code is assigned to the subcarrier corresponding to the "segment" after being modulated by "BoostedBPSK" to complete the "Preamble" modulation, so segmenting the PN code will not cause other Deviation from PAPR. After the sending groups are divided, the subcarriers included in each sending group are sent to the transmitting antenna corresponding to the sending group among the M transmitting antennas of the base station.

Step 101, through the transmitting antennas corresponding to the sending groups, sequentially perform guard sideband processing, inverse Fourier transform processing, and cyclic prefix processing on the subcarriers included in the corresponding sending groups, and modulate them into radio frequency Perform broadcast transmission.

After the transmitting antennas of the base station receive the subcarriers to be sent, they first add guard sidebands to the subcarriers, that is, set "0" on the subcarriers without data and the guard subcarriers; then, after DC bias processing (DC-SHIFT ) and then inverse Fourier transform (IFFT) to transform to the time domain and add a cyclic prefix (Cyclic Prefix; hereinafter referred to as: CP), and then modulate to radio frequency transmission.

Since the number of data subcarriers sent by each transmit antenna is 1/M of that transmitted by a single antenna, under the premise that the total power of each transmit antenna remains unchanged, the power of each "preamble" subcarrier is the power of the subcarrier transmitted by a single antenna M times, thereby increasing the downlink channel of the base station, such as the coverage of the synchronization/broadcast/control channel and improving the signal-to-noise ratio received by the user equipment, ensuring that the user equipment can reliably decode the synchronization/broadcast/control information sent by the base station, and increasing the cell edge coverage to increase throughput.

When the base station transmits the "preamble" signal using the method of the above embodiment, for the UE side, the existing technology can be used to estimate the received "preamble" signal, and accurate reception can be achieved without any modification.

FIG. 5 is a flowchart of Embodiment 2 of the subcarrier transmission method of the present invention, and FIG. 6 is a schematic diagram of a multi-antenna subcarrier allocation scheme of Embodiment 2 of the subcarrier transmission method of the present invention. As shown in FIG. 5 and FIG. 6 , the multiple The antenna omni-directional beamforming method is described by taking the base station sending the FCH and DL_MAP signals in the OFDMA frame structure in the WiMAX system as an example, including:

Step 200: Divide several subcarriers on the entire frequency band of signals located in the use part of the subchannel arrangement domain into several physical clusters, so that each physical cluster contains pilot subcarriers, and the pilot subcarriers are used for For user equipment to perform channel estimation and obtain channel information of data subcarriers in the physical cluster;

Step 201, according to the mapping relationship between logical clusters and the physical clusters, rearrange several subcarriers on the entire frequency band of the signals in the domain using partial subchannel arrangement, and average the several subcarriers in units of the logical clusters The M transmitting antennas assigned to the base station perform broadcast transmission.

In this embodiment, the FCH and DL_MAP signals are used as an example of the signals located in the used part of the sub-channel arrangement domain for illustration.

FCH and DL_MAP are located in the first partial usage of sub-channels (Partial Usage of Sub-channels; hereinafter referred to as: PUSC) arrangement domain in the downlink OFDMA frame structure. On the logical frame, FCH is located in the first four slots (slots) of its corresponding "segment", followed by DL_MAP, and arranged according to frequency priority. It is proposed to allocate multi-antenna subcarriers on the physical frame, and divide the FCH and DL_MAP signals into several physical clusters. As the data located in the PUSC permutation domain, the user equipment needs to use the cluster as a unit to perform channel estimation by using the pilot frequency at a fixed position in each physical cluster, and linearly interpolate and extrapolate the channel. Therefore, it is necessary to ensure that the data in the same physical cluster is allocated to the same transmit antenna for transmission. The specific method is as follows: First, map the FCH and DL_MAP information to the logical frame according to the mapping relationship specified in the protocol, and after rearranging the logical cluster (logical cluster) to the physical cluster (physical cluster) PUSC, the subframes including the pilot Carriers are evenly allocated to M transmit antennas at the base station in units of clusters.

The following is an example to illustrate, as shown in Table 1, for example, the system parameter 10MHz bandwidth 1024-FFT, FCH and DL_MAP signals have 840 pilot and data subcarriers in the entire frequency band ("841" in Table 1, of which there are 1 DC subcarriers), which can be divided into 60 physical clusters, and each physical cluster includes pilot subcarriers for user equipment to perform channel estimation. According to the mapping relationship between logical clusters and physical clusters, the mapping relationship between logical clusters and physical clusters is updated according to the "rearrangement order" in the protocol table 1, and the 840 subcarriers are rearranged. Assume that the FCH signal occupies the first 4 logical clusters of the logical frame, that is, when sending FCH data, the transmitted subcarriers are included in the physical clusters PC6, PC48, PC37 and PC21 corresponding to the logical clusters LC0, LC1, LC2 and LC3 respectively subcarriers.

Table 1

parameters value left guard subcarrier 92 Right guard subcarrier 91 The number of subcarriers used 841 rearrange the order 6, 48, 37, 21, 31, 40, 42, 56, 32, 47, 30, 33, 54, 18, 10, 15, 50, 51, 58, 46, 23, 45, 16, 57, 39, 35, 7, 55, 25, 59, 53, 11, 22, 38, 28, 19, 17, 3, 27, 12, 29, 26, 5, 41, 49, 44, 9, 8, 1, 13, 36, 14, 43, 2, 20, 24, 52, 4, 34, 0 The number of subcarriers per cluster 14 number of clusters 60

It can be seen from the above that under the premise that the total power of a single transmitting antenna remains unchanged, the average power of each transmitting antenna subcarrier in the multi-transmitting antenna omnidirectional beamforming scheme is M times that of a single transmitting antenna omnidirectional transmission. It can ensure that the data received by the user equipment in the same physical cluster are all sent by the same base station transmitting antenna, so that the user equipment can perform channel estimation on its pilot and estimate other sub-groups in the cluster through interpolation and extrapolation. The channel estimation value of the carrier, on the other hand, from the perspective of the receiving end, the average subcarrier power is improved by M times, thereby increasing the coverage of the downlink synchronization/broadcasting/control channel of the base station and improving the signal-to-noise ratio of the user equipment to ensure that the user equipment is The synchronization/broadcast/control information of the base station is reliably decoded, which increases the coverage of the cell edge and improves the throughput.

The above embodiments introduce the processing manner at the base station side. For the user equipment, since the FCH and DL_MAP signals are transmitted according to the PUSC arrangement, when the user equipment estimates the channel, the channel information on the data subcarrier should be interpolated and extrapolated by the pilot channel information in each physical cluster It is obtained by derivation, but channel estimation cannot be performed by interpolation between physical clusters. Using multiple antennas for omnidirectional beam broadcasting can increase the average transmit power of each subcarrier, thereby obtaining a greater signal-to-noise ratio in user equipment, and whether the base station uses multiple antennas for omnidirectional broadcast transmission is transparent to user equipment. That is, the processing mode of the receiving end has nothing to do with whether the base station uses multiple antennas for transmission, so that any modification to the user equipment can be avoided.

In the above embodiments, when several subcarriers of the signal to be transmitted in the entire frequency band are broadcast and transmitted through multiple transmitting antennas, it can also be combined with antenna switching transmission, that is, the transmission subcarriers are broadcast and transmitted in the manner of transmitting antenna switching transmission, which can further improve Performance of downlink multi-antenna omnidirectional beamforming.

Fig. 7 is a schematic diagram of antenna switching in the embodiment of the present invention. In this embodiment, the transmission of the "Preamble" signal in the OFDMA frame structure in the WiMAX system is taken as an example for illustration. Each wireless frame of the M-segment "Preamble" sequence separated in the frequency domain Transmit with different antenna switching patterns. The benefits brought by this are on the one hand, the power gain in the multi-antenna omnidirectional beam scheme, and on the other hand, the antenna selection gain, which can also be called frequency hopping gain, which can further improve the downlink omnidirectional channel performance.

The antenna switching refers to that in wireless communication, the fading characteristics of the wireless channel may cause short-term deep fading of the wireless signal. The same user sends signals to avoid one or more antenna channels among the multiple transmitting antennas from fading all the time, which can offset the influence of partial fading and bring antenna switching gain. The antenna switching pattern refers to how to select the antenna switching mode to send data each time. For example, in the embodiment of the present invention, when four antennas are used to send data, the same frequency domain data can be transmitted according to the antenna {0, 1, 2, 3} The order is switched and sent sequentially, or it can be switched in the manner of {0, 2, 3, 1}, or other, the switching method in {...} is the switching pattern.

There may be various schemes for antenna switching patterns, and this embodiment only lists a simple scheme for illustration, and of course this embodiment is also applicable to FCH and DL_MAP signals.

The above embodiment is only illustrated by broadcasting and sending the first three "OFDM symbol" signals in the downlink information frame as an example, but is not limited thereto.

In WiMAX, cyclic delay diversity (Cyclic Delay Diversity; hereinafter referred to as: CDD) can be used for multi-antenna transmission of the "OFDM symbol" signal, and the solution provided by the embodiment of the present invention can also be used for omnidirectional beamforming transmission. CDD is a multi-antenna transmission method adopted in WiMAX or Long Term Evolution (hereinafter referred to as: LTE). To simulate multipath signals, the receiving end adopts a similar principle of multipath combination to improve demodulation performance.

In addition, the physical broadcast channel (Physical Broadcast Channel; hereinafter referred to as: PBCH) and synchronization channel (Synchronization Channel; hereinafter referred to as: SCH) in LTE, etc. can also adopt the solution provided by the embodiment of the present invention to increase the channel coverage through power gain, Solve the problem of limited cell edge synchronization/broadcast/control, ensure that user equipment can reliably decode the synchronization/broadcast/control information sent by the base station, increase cell edge coverage and improve throughput.

Those of ordinary skill in the art can understand that all or part of the steps for realizing the above-mentioned method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the It includes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other various media that can store program codes.

FIG. 8 is a schematic structural diagram of a base station according to an embodiment of the present invention. As shown in FIG. 8 , the base station includes an allocation processing module 11 and M transmitting antennas 12 (M≥2), wherein the allocation processing module 11 is used to distribute signals to be transmitted over the entire frequency band The several subcarriers on the frequency band are divided into several transmission groups, and the several subcarriers of the signal to be transmitted on the entire frequency band are allocated to the M transmitting antennas 12 of the base station in units of transmission groups; the transmitting antennas 12 are used to allocate subcarriers for broadcast transmission.

The base station provided in this embodiment is suitable for broadcasting and sending the first three "OFDMsymbol" signals in the downlink information frame. The allocation processing module 11 may include a first division unit and a first allocation unit to be suitable for sending the "Preamble" signal. The allocation processing module 11 The first division unit in the "Preamble" signal is evenly distributed in several subcarriers on the entire frequency band and is divided into M transmission groups in sequence, and the first allocation unit sends the subcarriers included in each transmission group to the M transmission antennas. The transmitting antenna 12 corresponding to the sending group; then the subcarriers included in the sending group are sequentially subjected to guard sideband processing, inverse Fourier transform processing, and cyclic prefix processing by the corresponding transmitting antenna 12, and are modulated to a radio frequency for broadcasting send.

In addition, the allocation processing module 11 may include a second division unit, a rearrangement unit, and a second allocation unit to be suitable for sending FCH and DL_MAP signals, and the second division unit in the allocation processing module 11 will be located in the FCH and DL_MAP using the PUSC column domain. The several subcarriers of the signal in the entire frequency band are divided into several physical clusters, so that each physical cluster contains a pilot subcarrier, and the pilot subcarrier is used for the user equipment to perform channel estimation and obtain the information in the physical cluster. The channel information of the data sub-carrier; then, according to the mapping relationship between the logical cluster and the physical cluster, rearrange the several sub-carriers located in the entire frequency band using the PUSC arrangement domain through the rearrangement unit; finally, through the second allocation unit A number of subcarriers are evenly allocated to the M transmitting antennas 12 of the base station in units of logical clusters, and then the transmitting antennas 12 broadcast and transmit the subcarriers allocated by the allocation processing module 11 .

The base station provided by the above-mentioned embodiments further includes a control module 13 for controlling the transmitting antenna 12 to broadcast and transmit several subcarriers of the signal to be transmitted in the entire frequency band by switching the transmitting antenna. In this embodiment, the multi-antenna omni-directional beam transmission and antenna switching are combined through the control module 13, so that antenna switching is performed for each wireless frame of the same frequency domain position data and a different antenna is selected for transmission. It can also be considered that the data sent by each antenna performs frequency hopping on each radio frame, which can additionally bring a certain antenna selection gain or frequency switching gain.

For the functions of each module in the base station provided by the above embodiments and the mutual cooperation to complete information broadcasting and sending, please refer to the relevant content in the above method embodiments. The base station can not only broadcast the first three signal information of the downlink OFDMA frame, but also In the OFDMA system, only a single-antenna omnidirectional channel can be used for broadcasting, thereby increasing the coverage of the downlink synchronization/broadcast/control channel of the base station and improving the signal-to-noise ratio received by the user equipment, ensuring that the user equipment can send synchronization/broadcast/control information to the base station Perform reliable decoding, increase cell edge coverage and improve throughput.

An embodiment of the present invention also provides a subcarrier transmission system, including a base station and a user equipment for receiving the subcarriers broadcast by the base station, where the involved base station can be the base station provided in the above embodiment, and its structure and function are as follows I won't repeat them here. In the system provided in this embodiment, the base station can increase the coverage of the downlink synchronization/broadcast/control channel and improve the signal-to-noise ratio received by the user equipment, so as to ensure that the user equipment can reliably decode the synchronization/broadcast/control information sent by the base station. Cell edge coverage and improved throughput.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (6)

1. a sub-carrier sending method is characterized in that, comprising:

Signal to be sent several subcarriers on whole frequency are divided into several transmission groups, are that unit broadcasts transmission for the M transmit antennas of base station said signal to be sent several subcarrier allocation on whole frequency with said transmission group, wherein M >=2; Said method specifically comprises:

To be positioned at signal several subcarriers on whole frequency that use the parton channel to arrange the territory and be divided into several physical cluster; Make all to include pilot sub-carrier in each said physical cluster that said pilot sub-carrier is used for the channel information that supplies subscriber equipment to carry out channel estimating and obtain said physical cluster data subcarrier;

Mapping relations according to Logic Cluster and said physical cluster; Rearrangement is positioned at uses the parton channel to arrange several subcarriers of signal on whole frequency in territory, and is that unit broadcasts transmission with said several subcarrier mean allocation to the M transmit antennas of base station with said Logic Cluster.

2. subcarrier sending method according to claim 1 is characterized in that, said method also comprises:

Several subcarriers order that signal to be sent is evenly distributed on the whole frequency evenly is divided into M transmission group, and the included subcarrier of each said transmission group is sent in the M transmit antennas and the corresponding transmitting antenna of said transmission group;

Through with the corresponding transmitting antenna of said transmission group, the included subcarrier of each self-corresponding transmission group is added edge protection tape handling, Fourier inversion successively handles and add circulation prefix processing, and broadcast transmission after being modulated to radio frequency.

3. subcarrier sending method according to claim 1 and 2 is characterized in that, said method also comprises:

Adopt transmitting antenna to switch the mode of sending, said signal to be sent several subcarriers on whole frequency are sent in broadcasting.

4. a base station is characterized in that, comprising:

The allocation process module; Be used for signal to be sent several subcarriers on whole frequency are divided into several transmission groups; And to be unit with said transmission group give the M transmit antennas of base station, wherein M >=2 with said signal to be sent several subcarrier allocation on whole frequency;

Transmitting antenna is used for the subcarrier of said allocation process module assignment is broadcasted transmission;

Wherein, said allocation process module comprises:

Second division unit; Be used for to be positioned at signal several subcarriers on whole frequency that use the parton channel to arrange the territory and be divided into several physical cluster; Make each physical cluster all include pilot sub-carrier, said pilot sub-carrier is used for the channel information that supplies subscriber equipment to carry out channel estimating and obtain said physical cluster data subcarrier;

Reset the unit, be used for mapping relations, reset to be positioned at and use the parton channel to arrange several subcarriers of signal on whole frequency in territory according to Logic Cluster and said physical cluster;

Second allocation units, being used for said Logic Cluster is the M transmit antennas that unit gives said several subcarrier mean allocation the base station.

5. base station according to claim 4 is characterized in that, also comprises:

Control module is used to control said transmitting antenna and adopts transmitting antenna to switch the mode of sending, and said signal to be sent several subcarriers on whole frequency are sent in broadcasting.

6. a sub-carrier transmitting system comprises like claim 4 or 5 described base stations and the subscriber equipment that is used to receive the subcarrier that said base station broadcast sends.

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