CN101335553B - Method and apparatus implementing broadcast channel covering by antenna array - Google Patents

Abstract

The invention relates to a method for realizing broadcast channel covering by an antenna array, which is used in a smart antenna system, the method includes the following steps that: step 1. according to the coverage condition of communities/sectors, the steering of the antenna array broadcast beam and the half power width of the broadcast beam are calculated; step 2. the broadcast beam steering is takn as a center, N sub-beams (N is a natural number) with symmetric steering are set up according to the calculation results; step 3. on the basis of the interval of transmission time or the integral multiple of the transmission time, broadcasting channel information is emitted by adopting the N sub-beams. The invention can acquire higher beam gain, modify the disequilibrium of the coverage area for broadcast channels and dedicated channels, and promote the network performance of the system.

Description

A kind of aerial array is realized method and the device that broadcast channel covers

Technical field

The present invention relates to wireless communication system, relate in particular to method and device that a kind of aerial array realizes that broadcast channel covers.

Background technology

Aerial array is mainly used in antenna system; Smart antenna is meant spatial character and the Digital Signal Processing that utilizes the signal transmission; Can realize airspace filter and wave beam forming to the service signal of the dedicated channel that receives, reduce noise jamming, increase capacity, enlarge and cover, improve communication quality, reduce transmitting power and improve the purpose of wireless data transmission rate thereby reach.

To down link, the beam gain of smart antenna comprises the power gain and the wave beam forming gain of many antennas.Power gain is meant the gain of the transmitting power sum of all antennas with respect to single-antenna transmission power, if the transmitting power of each antenna equates that then the power gain theoretical value is 101g (M); Wave beam forming gain is meant the signal power that merges at the subscriber equipment receiving terminal homophase gain with respect to single-antenna case that transmits of many antennas; If each antenna transmit fully relevant and power equates; Then under white Gaussian noise and single footpath environment, wave beam forming gain theory value is 101g (M).Consider the fluctuation of beam gain under the different angles, in the practical application, beam gain adopts the beam gain average in the half-power beam width.For up link, only comprise wave beam and form gain, also claim the airspace filter gain, i.e. the gain of many antenna receiving signals homophase merging is mainly used in the inhibition noise.

Dedicated channel (DCH) is the uplink and downlink transmission channel of a kind of user of carrying or control information; To different user terminals, adopt directional beam figuration technology, except that power gain; Can also further obtain figuration gain, improve the reception Signal to Interference plus Noise Ratio of subscriber equipment.

Broadcast channel (BCH) is one of main type of downlink common transport channel; Usually require the employing broadcast beam to form and realize that full cell/section covers, guarantee that promptly the user terminal in the coverage all can receive and relevant system broadcasts or the customizing messages of accurate demodulation.Compare with dedicated channel, broadcast channel adopts the omnidirectional of not distinguishing user terminal to cover, and causes figuration gain significantly to reduce, thereby possibly aggravate the disequilibrium of system broadcast channel and dedicated channel coverage, causes the grid decreased performance.

Patent application " array antenna is realized the method and apparatus that omnidirectional covers " (application number: CN200310115732; Publication number: CN1622491; Open day: on June 1st, 2005) with corresponding M the transmitting antenna of M transmission channel; With corresponding M the transmission channel of M random sequence, each random sequence of usefulness is as the weight coefficient sequence, and the common channel signal of corresponding transmission channel is carried out weighting; The common channel signal of each transmission channel after the weighting send the emission of corresponding antenna array element, and M is the positive integer greater than 1.This method need not to adopt the control information of the bay and the transmission channel of powerful power amplifier and high-gain; Thereby simplified system configuration; But do not improve the figuration gain of broadcast channel, for the environment that sighting distance directly is dominant, more as if antenna number M; The broadcast channel received power fluctuation that possibly cause user terminal significantly increases, and greatly influences processes such as the user inserts at random, switching.

Summary of the invention

The technical problem that the present invention will solve has provided method and the device that a kind of aerial array realizes that broadcast channel covers, and solves the problem how array antenna realizes that broadcast channel covers.

The invention provides the method that a kind of aerial array realizes that broadcast channel covers, be used for antenna system, comprising:

Step 1 according to the coverage condition of cell/section, is calculated the sensing of aerial array broadcast beam and the half-power width of broadcast beam;

Step 2 is oriented to the center with broadcast beam, according to result of calculation N beamlet pointing to symmetry is set, and N is a natural number;

Step 3 based on Transmission Time Interval or its integral multiple, adopts said N sub-beam transmission broadcast channel information.

In the step 2; The half-power width of each beamlet is greater than the 1/N of broadcast beam half-power width; And be not less than the business beam half-power width of aerial array dedicated channel, the gain of beamlet is higher than the gain of broadcast beam, and is no more than the business beam gain of aerial array dedicated channel.

In the step 3, adopt N beamlet to switch the emission broadcast channel information successively or alternately.

If N is an odd number, then the sensing of N beamlet is followed successively by the satisfied following relation of sensing of each beamlet:

$\frac{{\mathrm{\θ}}_S^n+{\mathrm{\θ}}_S^{-n}}{2}={\mathrm{\θ}}_B$

${\mathrm{\θ}}_S^{-(N-1)/2}={\mathrm{\θ}}_B-\frac{{\mathrm{\Ω}}_B}{2}+\frac{{\mathrm{\Ω}}_S}{2}$

${\mathrm{\θ}}_S^{(N-1)/2}={\mathrm{\θ}}_B+\frac{{\mathrm{\Ω}}_B}{2}-\frac{{\mathrm{\Ω}}_S}{2};$

Wherein, ${\mathrm{\&theta;}}_S^{-(N-1)/2}<...<{\mathrm{\&theta;}}_S^0<...<{\mathrm{\&theta;}}_S^{(N-1)/2},$ ${\mathrm{\&theta;}}_S^0={\mathrm{\&theta;}}_B,$ N=1 ..., (N-1)/2, θ _BBe the sensing of aerial array broadcast beam, Ω _BBe broadcast beam half-power width, Ω _SBe each beamlet half-power width;

If N is an even number, then the sensing of N beamlet is followed successively by the satisfied following relation of sensing of

each beamlet:

$\frac{{\mathrm{\&theta;}}_S^n+{\mathrm{\&theta;}}_S^{-n}}{2}={\mathrm{\&theta;}}_B$

${\mathrm{\&theta;}}_S^{-N/2}={\mathrm{\&theta;}}_B-\frac{{\mathrm{\&Omega;}}_B}{2}+\frac{{\mathrm{\&Omega;}}_S}{2}$

${\mathrm{\&theta;}}_S^{N/2}={\mathrm{\&theta;}}_B+\frac{{\mathrm{\&Omega;}}_B}{2}-\frac{{\mathrm{\&Omega;}}_S}{2};$

Wherein, ${\mathrm{\&theta;}}_S^{-N/2}<...<{\mathrm{\&theta;}}_S^{-1}<{\mathrm{\&theta;}}_S^1<...<{\mathrm{\&theta;}}_S^{N/2},$ N=1 ..., N/2, θ _BBe the sensing of aerial array broadcast beam, Ω _BBe the half-power width of broadcast beam, Ω _SHalf-power width for each beamlet.

Adopt be spaced apart mT the switching time of N beamlet, m=1,2 ..., m≤16, T is a Transmission Time Interval.

It is characterized in that N≤4.

The invention provides the device that a kind of aerial array realizes that broadcast channel covers, comprising:

Beam position and half-power width computing module are used for the coverage condition according to cell/section, calculate the sensing of aerial array broadcast beam and the half-power width of broadcast beam;

Beamlet is provided with module, is used for being oriented to the center with broadcast beam, according to result of calculation N beamlet pointing to symmetry is set, and N is a natural number;

The broadcast channel information transmitter module is used for based on Transmission Time Interval or its integral multiple, adopts said N sub-beam transmission broadcast channel information.

Be provided with in the module in said beamlet; The half-power width of each beamlet is greater than the 1/N of broadcast beam half-power width; And be not less than the business beam half-power width of aerial array dedicated channel; The gain of beamlet is higher than the gain of broadcast beam, and is no more than the business beam gain of aerial array dedicated channel.

In said broadcast channel information transmitter module, adopt N beamlet to switch the emission broadcast channel information successively or alternately.

The present invention can obtain higher beam gain, improves the disequilibrium of broadcast channel and dedicated channel coverage, improves the network performance of system.

Description of drawings

Fig. 1 is that aerial array provided by the invention is realized the flow chart that broadcast channel covers;

Fig. 2 is that aerial array provided by the invention is realized the installation drawing that broadcast channel covers.

Embodiment

The invention provides a kind of aerial array broadcast channel and cover implementation method; Promptly through a plurality of beamlet are set; And, adopt a plurality of beamlet to switch the emission broadcast channel information successively or alternately, thereby realize that broadcast channel covers based on Transmission Time Interval (TTI) or its integral multiple.

It is following, as shown in Figure 1 that a kind of aerial array broadcast channel of the embodiment of the invention covers implementation method:

Step 10 based on the coverage condition of cell/section, is confirmed the sensing of aerial array broadcast beam and the half-power width of broadcast beam.

Wherein, the aerial array broadcast beam is oriented to θ _B, the half-power width of broadcast beam (beamwidth) is Ω _BThe gain table of broadcast beam is shown ρ _B

Step 20; Be oriented to the center with broadcast beam, be provided with and point to symmetry, have N beamlet of certain gain, wherein the half-power width of each beamlet is greater than the 1/N of broadcast beam half-power width; The gain of beamlet is higher than the gain of broadcast beam, and N is a natural number.

The beamlet number is N, and the half-power width of beamlet is Ω _S, ${\mathrm{\&Omega;}}_S>\frac{{\mathrm{\&Omega;}}_B}{N},$ And Ω _SBe not less than the business beam half-power width of aerial array dedicated channel; The beamlet gain table is shown ρ _S, ρ _S>ρ _B, and ρ _SShould be no more than the business beam gain of aerial array dedicated channel.Sensing according to beamlet is followed successively by 1,2 by little sequence number extremely big or that by big extremely little order beamlet is set ..., N.

If N is an odd number, then the sensing of N beamlet is followed successively by

Wherein ${\mathrm{\&theta;}}_S^{-(N-1)/2}<...<{\mathrm{\&theta;}}_S^0<...<{\mathrm{\&theta;}}_S^{(N-1)/2},$ ${\mathrm{\&theta;}}_S^0={\mathrm{\&theta;}}_B,$

With

With θ _BFor satisfying symmetric relation in the center, n=1 ..., (N-1)/2, promptly

$\frac{{\mathrm{\&theta;}}_S^n+{\mathrm{\&theta;}}_S^{-n}}{2}={\mathrm{\&theta;}}_B---\left(1\right)$

${\mathrm{\&theta;}}_S^{-(N-1)/2}={\mathrm{\&theta;}}_B-\frac{{\mathrm{\&Omega;}}_B}{2}+\frac{{\mathrm{\&Omega;}}_S}{2}---\left(2\right)$

${\mathrm{\&theta;}}_S^{(N-1)/2}={\mathrm{\&theta;}}_B+\frac{{\mathrm{\&Omega;}}_B}{2}-\frac{{\mathrm{\&Omega;}}_S}{2}---\left(3\right)$

If N is an even number, then the sensing of N beamlet is followed successively by

Wherein ${\mathrm{\&theta;}}_S^{-N/2}<...<{\mathrm{\&theta;}}_S^{-1}<{\mathrm{\&theta;}}_S^1<...<{\mathrm{\&theta;}}_S^{N/2},$

With With θ _BFor satisfying symmetric relation in the center, n=1 ..., N/2, promptly

$\frac{{\mathrm{\&theta;}}_S^n+{\mathrm{\&theta;}}_S^{-n}}{2}={\mathrm{\&theta;}}_B---\left(4\right)$

${\mathrm{\&theta;}}_S^{-N/2}={\mathrm{\&theta;}}_B-\frac{{\mathrm{\&Omega;}}_B}{2}+\frac{{\mathrm{\&Omega;}}_S}{2}---\left(5\right)$

${\mathrm{\&theta;}}_S^{N/2}={\mathrm{\&theta;}}_B+\frac{{\mathrm{\&Omega;}}_B}{2}-\frac{{\mathrm{\&Omega;}}_S}{2}---\left(6\right)$

Step 30 based on Transmission Time Interval (TTI) or its integral multiple, adopts N beamlet to switch the emission broadcast channel information successively or alternately, thereby realizes that broadcast channel covers.

The time interval of TTI is expressed as T, then utilizes be spaced apart mT the switching time of N beamlet, m=1, and 2 ..., common m≤16.Subscriber equipment demodulating system broadcast message minimum is the cycle with TTI, therefore with TTI or its integral multiple as being switching time at interval in order to guarantee the stability of the broadcast singal power that subscriber equipment receives in the demodulating process.Realize that the time that the full cell/section broadcast channel of single covers is mTN.

The switching of beamlet mainly comprises dual mode.First kind, beamlet presses 1,2 ..., the order of N is switched successively; Second kind, beamlet is by 1, N, 2, N-1 ... sequence alternate switch.

Beamlet is counted choosing of N need take all factors into consideration factors such as beam gain and broadcasting cover time.N is big more, and the beamlet width is more little, and beam gain is high more, but realizes that the time that the full cell/section broadcasting of single covers will be long more, and the broadcast singal power fluctuation that subscriber equipment receives on the same orientation is risen to some extent; Otherwise, reduce N, though reduce the fluctuation and the broadcasting cover time of receiving broadcast signal power, the beamlet gain descends, and causes the broadcast channel coverage to reduce, usually N≤4.

Said method provided by the invention is through being provided with a plurality of beamlet, and based on Transmission Time Interval or its integral multiple, adopts a plurality of beamlet to switch the emission broadcast channel information successively or alternately, thereby realize that broadcast channel covers.Because the half-power width of beamlet is significantly less than the gain that the gain of half-power width and the beamlet of broadcast beam is higher than broadcast beam; Therefore can obtain higher beam gain; Improve the disequilibrium of broadcast channel and dedicated channel coverage, improve the network performance of system.

The present invention also provides a kind of aerial array to realize the device 22 that broadcast channel covers, and is as shown in Figure 2, comprises beam position and half-power width computing module 11, and beamlet is provided with module 21 and broadcast channel information transmitter module 31.Beam position and half-power width computing module 11 are used for the coverage condition according to cell/section, calculate the sensing of aerial array broadcast beam and the half-power width of broadcast beam; Beamlet is provided with module 21, is used for being oriented to the center with broadcast beam, according to result of calculation N beamlet pointing to symmetry is set, and N is a natural number; Broadcast channel information transmitter module 31 is used for based on Transmission Time Interval or its integral multiple, adopts said N sub-beam transmission broadcast channel information.

Those skilled in the art can also carry out various modifications to above content under the condition that does not break away from the definite the spirit and scope of the present invention of claims.Therefore scope of the present invention is not limited in above explanation, but confirm by the scope of claims.

Claims (5)

1. an aerial array is realized the method that broadcast channel covers, and is used for antenna system, it is characterized in that, comprising:

Step 1 according to the coverage condition of cell/section, is calculated the sensing of aerial array broadcast beam and the half-power width of broadcast beam;

Step 2 is oriented to the center with broadcast beam, and N beamlet pointing to symmetry is set according to result of calculation; N is a natural number; Wherein, the half-power width of each beamlet is greater than the 1/N of broadcast beam half-power width, and is not less than the business beam half-power width of aerial array dedicated channel; The gain of beamlet is higher than the gain of broadcast beam, and is no more than the business beam gain of aerial array dedicated channel;

Step 3 based on Transmission Time Interval or its integral multiple, adopts a said N beamlet to switch the emission broadcast channel information successively or alternately.

2. aerial array as claimed in claim 1 is realized the method that broadcast channel covers; It is characterized in that; If N is an odd number, then the sensing of N beamlet is followed successively by the satisfied following relation of sensing of

each beamlet:

$\frac{{\mathrm{\&theta;}}_S^n+{\mathrm{\&theta;}}_S^{-n}}{2}={\mathrm{\&theta;}}_B$

${\mathrm{\&theta;}}_S^{-(N-1)/2}={\mathrm{\&theta;}}_B-\frac{{\mathrm{\&Omega;}}_B}{2}+\frac{{\mathrm{\&Omega;}}_S}{2}$

${\mathrm{\&theta;}}_S^{(N-1)/2}={\mathrm{\&theta;}}_B+\frac{{\mathrm{\&Omega;}}_B}{2}-\frac{{\mathrm{\&Omega;}}_S}{2};$

Wherein,

N=1 ..., (N-1)/2, θ _BBe the sensing of aerial array broadcast beam, Ω _BBe broadcast beam half-power width, Ω _SBe each beamlet half-power width;

If N is an even number, then the sensing of N beamlet is followed successively by the satisfied following relation of sensing of

each beamlet:

$\frac{{\mathrm{\&theta;}}_S^n+{\mathrm{\&theta;}}_S^{-n}}{2}={\mathrm{\&theta;}}_B$

${\mathrm{\&theta;}}_S^{-(N-1)/2}={\mathrm{\&theta;}}_B-\frac{{\mathrm{\&Omega;}}_B}{2}+\frac{{\mathrm{\&Omega;}}_S}{2}$

${\mathrm{\&theta;}}_S^{(N-1)/2}={\mathrm{\&theta;}}_B+\frac{{\mathrm{\&Omega;}}_B}{2}-\frac{{\mathrm{\&Omega;}}_S}{2};$

Wherein,

N=1 ..., N/2, θ _BBe the sensing of aerial array broadcast beam, Ω _BBe the half-power width of broadcast beam, Ω _SHalf-power width for each beamlet.

3. aerial array as claimed in claim 1 is realized the method that broadcast channel covers, and it is characterized in that, adopts be spaced apart mT the switching time of N beamlet, m=1, and 2 ..., m≤16, T is a Transmission Time Interval.

4. realize the method that broadcast channel covers like claim 1,2 or 3 described aerial arrays, it is characterized in that N≤4.

5. an aerial array is realized the device that broadcast channel covers, and it is characterized in that, comprising:

Beam position and half-power width computing module are used for the coverage condition according to cell/section, calculate the sensing of aerial array broadcast beam and the half-power width of broadcast beam;

Beamlet is provided with module, is used for being oriented to the center with broadcast beam, and N beamlet pointing to symmetry is set according to result of calculation; N is a natural number; Wherein, the half-power width of each beamlet is greater than the 1/N of broadcast beam half-power width, and is not less than the business beam half-power width of aerial array dedicated channel; The gain of beamlet is higher than the gain of broadcast beam, and is no more than the business beam gain of aerial array dedicated channel;

The broadcast channel information transmitter module is used for based on Transmission Time Interval or its integral multiple, adopts a said N beamlet to switch the emission broadcast channel information successively or alternately.

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