CN1964339A - Software radio-based OFDM transmitting and receiving machine able to upgrade - Google Patents

Abstract

The OFDM BS transceiver comprises: a transmission system with a variable emission module and a receiving module, a software radio controller to control modules and set relative parameters, and a channel allocation controller to appoint sub-carrier for user. This invention is benefit to update system and terminal, and simple to application in real system.

Description

Based on the upgradeable OFDM transceiver of software radio

Technical field

The present invention relates to mobile radio system, particularly based on the upgradeable OFDM transceiver of software radio.

Background technology

Orthogonal frequency division multiplexi (being called for short OFDM) has become one of the most competitive wireless communication technology.At present many documents have been arranged ofdm system design and implementation, and this technology has obtained application (as 802.11,802.16 series such as grade) in real system.OFDM can be divided into broader frequency spectrum many little narrow-band sub-carriers, it can be in the environment of radio multi-user the transmitting high speed data signal.Especially this technology will be as more extremely common people's concern of effective means of wireless mobile communications of future generation.

Along with the continuous increase of technological progress and people's demand, mobile communication system is also constantly increased in the requirement aspect family and the office.In cellular mobile communication networks, how to use the OFDM technology to also have many problems to need to solve effectively.Especially inconsistent in the configuration of the frequency resource of different districts, use frequency spectrum to overlap and broader frequency spectrum sub-district and narrow band spectrum sub-district and when depositing, also lack the network equipment and terminal equipment total solution.Simultaneously, under the continuous upgrade case of travelling carriage and base station system, how to make the wide-band communication system after the renewal keep the backwards compatibility problem to be guaranteed by rational design.The structure of actual wireless network as shown in Figure 1.Wherein No. 0 sub-district service band is arrowband primary bandwidth W ₀, the frequency band of No. 1 sub-district use is broadband width W ₁Although in some wireless communication systems to upgrade problem and frequency cover more existing consider respectively, but in system constantly under upgrading and the multiband bandwidth overlay network environment, existing OFDM mobile communication equipment also lacks relevant art and processing means and finishes efficient communication between dissimilar users.

Summary of the invention

The purpose of this invention is to provide a kind of based on the upgradeable OFDM transceiver of software radio.

For achieving the above object, a kind of based on the upgradeable OFDM base station transceiver of software radio, comprising: the variable transmitter module and the transmission system of receiver module; And be used to control each module of emission system and receiving system and software wireless electric controller that parameter is provided with and the control system of assigning the channel allocation controller of subcarrier for each user.

The present invention can solve the signal transmission issues between the ofdm system of different bandwidth.The present invention has realized that dissimilar mobile subscribers finish wireless access function in the sub-district of different bandwidth.Be suitable for the graceful upgrade of system and terminal.And the inventive method is relatively simple for structure, is easy to use in real system.

Description of drawings

Fig. 1 is the wireless network environment schematic diagram;

Fig. 2 is the novel base station transceiver structural representation with software wireless electric control;

Fig. 3 is novel OFDM travelling carriage Transceiver Module schematic diagram based on the software wireless electric control;

Fig. 4 is traditional OFDM travelling carriage Transceiver Module schematic diagram;

Fig. 5 is the structure chart that different user uses different frequency bands.

Embodiment

The present invention has showed a kind of novel wideband OFDM system transceiver method and mechanism based on software radio.It can be applied to base station system and mobile station terminal system.Its structure is shown in Fig. 2 and 3.It comprises several sections: software wireless electric controller (Software Radio Controller, be called for short SRC), channel allocation controller (Channel allocation Controller, be called for short CAC), adaptive channel encoding and modulator (Adaptive Modulation Coder, be called for short AMC), adaptive decoding and demodulator (Adaptive De-Modulation Decoder is called for short ADMD), frequency multiplier, despreader, IFFT/FFT processor, Cyclic Prefix insert and remove, A/D and D/A converter (D/A, A/D), band pass filter (Band Pass Filter is called for short BPF) and radio frequency unit device (RF).This invention is described to have the base station of software radio and the difference of travelling carriage is: the base station has a plurality of data source input and output; Travelling carriage has only data source input and output.

Aspect emission system, when customer traffic enters this system, the software wireless electric controller requires and channel conditions according to QoS of customer, assigns the modulation of Adaptive Modulation and Coding device and coding mode (BPSK, QPSK, 8PSK, 16QAM; Convolution code and Turbo code).Then, the signal after the modulation go here and there and conversion and spread spectrum after, just be assigned to and carry out IFFT on the different subcarriers and handle by channel allocation controller (CAC).The employed subcarrier number of each user does not repeat mutually, and satisfies each subcarrier in the mutually orthogonal condition of sample point.For broadband user's signal, CAC is N for the subcarrier scope of its distribution _mFor the narrow-band user signal, CAC is N for the subcarrier scope of its distribution ₀After finishing the IFFT processing and also string is changed, need insert Cyclic Prefix with the elimination intersymbol interference.The digital to analog converter of its back (DAC) converts the digital signal of input to analog signal.Subsequently, this signal is finished from base band moving to intermediate-freuqncy signal by band pass filter (Band Pass Filter is called for short BPF).Centre frequency and the bandwidth of SRC control BPF.At last, signal waiting for transmission is adjusted to the frequency range that expectation is launched, behind feed antenna, just this signal is launched by radio frequency amplifier.

Aspect receiving system, its processing procedure is opposite with emission process.Sent to band pass filter from the signal that antenna receives, to obtain the band signal of expectation.After through DAC and removal cyclic prefix module, each user carries out FFT according to subcarrier that CAC assigns and handles.Then, despreading, adaptive de mediation decoding module (ADMC) detect each user's data stream.

In whole receive-transmit system, SCR is its nucleus module.It can control and dispose transceiver mode of operation and parameter according to high-level signaling, user type and channel conditions.It can control the IFFT/FFT treated length, AMC/ADMC pattern, BPF centre frequency and bandwidth, radio frequency amplifier.It should make wide bandwidth base station transmit and receive dissimilar users' signal, can make the broadband travelling carriage finish the transmission of signal at different districts again.

Each user can set up and maintenance and system synchronization in the system, and SRC can obtain the relevant information of each user and network from high level; Each sub-district has the spreading code of oneself, keeps quadrature between each spreading code; Each subcarrier spacing is fixed; Transmission channel characteristic is a flat fading, additive white Gaussian noise.

In broadband cell A is arranged ₁The broadband user and the A of the advanced transceiver of individual band ₀The narrow-band user of individual general transceiver.Advanced transceiver BTS can be respectively with transmitting data with the MS of advanced transceiver and common MS.At transmitter terminal, the modulated and coding of each user data, after the spread processing, it is W that each signal is mapped to bandwidth respectively ₁M _i(M ₀＜M ₁, 0＜M ₁＜N ₁, 0＜M ₀＜N ₀) on the different sub carrier frequency in the subcarrier.Baseband OFDM signal after IFFT handles can be expressed as

$s_l\left(t\right)=\left\{\begin{array}{cc}\frac{1}{\sqrt{T-T_{\mathrm{cp}}}}[\underset{i=0}{\overset{A_1-1}{\mathrm{\&Sigma;}}}{s}_1^i\left(t\right)+\underset{j=0}{\overset{A_0-1}{\mathrm{\&Sigma;}}}{s}_0^m\left(t\right)]& 0\&le;t\&le;T\\ 0& t<0\mathrm{ort}>T\end{array}---\left(1\right)\right.$

T=N in the formula ₁/ W ₁+ Tcp=N ₁/ W ₁+ Tcp is a symbol duration, and Tcp is the duration of Cyclic Prefix, $s_1^i\left(t\right)=\underset{k=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_k^i\exp \left[j\frac{2\mathrm{\&pi;}}{N_1}{W}_{1}k(t-T_{\mathrm{cp}})\right]$ Be broadband signal, $s_0^m\left(t\right)=\underset{k=0}{\overset{M_0-1}{\mathrm{\&Sigma;}}}{d}_k^m\exp \left[j\frac{2\mathrm{\&pi;}}{N_0}{W}_{0}k(t-T_{\mathrm{cp}})\right]$ Be narrow band signal, M ₁And M ₀Be in the wideband frequency and the interior available sub-carrier number of narrow band frequency, $d_k^i=b^i{v}_k^i$ The IFFT data bit of indicating to transmit, v _k ⁱ(as $v_k^i=1,$ Then $v_k^j=0j\&NotEqual;i$ ) represent that k subcarrier is shared by i-user.W ₁And W ₀Broadband user's signal and narrow-band user signal transfer bandwidth.The signal of OFDM series of symbols output is:

$s\left(t\right)=\underset{l=-\&infin;}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{s}_l(t-\mathrm{lT})t){\mathrm{\&Pi;}}_T(t-\mathrm{lT})---\left(2\right)$

This signal series is by behind the wireless channel (multipath fading and AWGN), and the signal of receiving at receiving terminal is

$r\left(t\right)={\&Integral;}_{-\&infin;}^{\&infin;}h(\mathrm{\&tau;},t)s(t-\mathrm{\&tau;})\mathrm{d\&tau;}+n\left(t\right)---\left(3\right)$

(τ t) is the impulse response of physical channel to h in the formula, and n (t) is an additive white Gaussian noise.The OFDM receiver behind ADC and the removal CP, mates the waveform that transmits with one group of fft processor at [Tcp, T] through frequency translation.Each subcarrier impulse response is

$g_{k,l}\left(t\right)=\left\{\begin{array}{cc}\exp [-j\frac{2\mathrm{\&pi;}}{n_l}{W}_{l}k(T-t)]& t\&Element;[T_{\mathrm{cp}},T]\\ 0& \mathrm{otherwise}\end{array}\right.---\left(4\right)$

Wherein l represents different user types (l=1 broadband user, l=0 narrow-band user).The FFT of k subcarrier is output as the user.K OFDM symbol is output as

$y_{k,l}=[r\left(t\right)\&CircleTimes;g_{k,l}\left(t\right)]{|}_{t=T}={\&Integral;}_{-\&infin;}^{\&infin;}r\left(t\right)g_{k,l}(T-t)\mathrm{dt}$

$={\&Integral;}_{T_{\mathrm{cp}}}^T{\&Integral;}_0^{T_{\mathrm{cP}}}h(t,\mathrm{\&tau;})s(t-\mathrm{\&tau;})\mathrm{d\&tau;exp}(-j2\mathrm{\&pi;}\frac{W_1}{N_1}\mathrm{kt})\mathrm{dt}+{\&Integral;}_{T_{\mathrm{cp}}}^{T}n\left(t\right)\exp (-j2\mathrm{\&pi;}\frac{W_1}{N_1}\mathrm{kt})\mathrm{dt}---\left(5\right)$

Remain unchanged as the characteristic of channel in an OFDM interval, channel impulse response is h (τ).I broadband user is at T _Cp＜t＜T and 0＜τ＜T _CpSufficient statistic during this time is output as

$y_{k,1}^i=\underset{k\&prime;=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_{k\&prime;}^i{\&Integral;}_{T_{\mathrm{cp}}}^T{\&Integral;}_0^{T_{\mathrm{cp}}}h\left(\mathrm{\&tau;}\right)\frac{\exp [j2\mathrm{\&pi;}\frac{W_1}{N_1}k\&prime;(t-\mathrm{\&tau;}-T_{\mathrm{cp}})]}{\sqrt{T-T_{\mathrm{cp}}}}\mathrm{d\&tau;}\frac{\exp [-j2\mathrm{\&pi;}\frac{W_1}{N_1}k(t-T_{\mathrm{cp}})}{\sqrt{T-T_{\mathrm{cp}}}}\mathrm{dt}+n_k$

$=\underset{k\&prime;=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_{k\&prime;}^i{{\&Integral;}_{T_{cp}}^{T}h}_{k\&prime;}\frac{\exp [j2\mathrm{\&pi;k}\&prime;\frac{W_1}{N_1}(t-T_{\mathrm{cp}})]}{T-T_{\mathrm{cp}}}\exp (-j2\mathrm{\&pi;}\frac{W_1}{N_1}k(t-T_{\mathrm{cp}})\mathrm{dt}+n_k---\left(6\right)$

$=\underset{k\&prime;=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_{k\&prime;}^i{h}_{k\&prime;}\mathrm{\&delta;}(k\&prime;-k)+n_k$

$=d_k^i{h}_k+n_k$

Wherein $h_{k^{\&prime;}}={\&Integral;}_0^{T_{\mathrm{CP}}}h\left(\mathrm{\&tau;}\right)\exp (-j2\mathrm{\&pi;}\frac{W_1}{N_1}k\&prime;\mathrm{\&tau;})\mathrm{d\&tau;}$ It is the frequency response of the sampling of channel. $n_k={\&Integral;}_{T_{\mathrm{cp}}}^{T}n\left(t\right)\exp (-j2\mathrm{\&pi;}\frac{W_1}{N_1}\mathrm{kt})\mathrm{dt}$ Be that average is zero Gaussian noise.The span of k from 0 to M ₁-1.Effectively the emission band scope is B ₁(B ₁＜W ₁).

For narrow-band user, the signal after its receiver demodulation is given by following formula:

$y_{m,0}^j=\underset{k\&prime;=0}{\overset{M_0-1}{\mathrm{\&Sigma;}}}{d}_{k\&prime;}^i{\&Integral;}_{T_{\mathrm{cp}}}^T{\&Integral;}_0^{T_{\mathrm{cp}}}h\left(\mathrm{\&tau;}\right)\frac{\exp [j2\mathrm{\&pi;}\frac{W_0}{N_0}k\&prime;(t-\mathrm{\&tau;}-T_{\mathrm{cp}})}{\sqrt{T-T_{\mathrm{cp}}}}\mathrm{d\&tau;}\frac{\exp [-j2\mathrm{\&pi;}\frac{W_0}{N_0}m(t-T_{\mathrm{cp}})}{\sqrt{T-T_{\mathrm{cp}}}}\mathrm{dt}+n_m$

$=d_m^j{h}_m+n_m---\left(7\right)$

Wherein the span of narrow-band user transmission subcarrier Coefficient m from 0 to M ₀-1.Corresponding effectively transmission bandwidth is B ₀(B ₀＜W ₀).

When the broadband travelling carriage with advanced transceiver enters the sub-district, arrowband, after they can adjust and change the module parameter of transceiver, communicate with the arrowband base station transceiver.The parameter of adjusting comprises the bandwidth W of band pass filter ₀, the number N of IFFT/FFT ₀Wait other parameter.

Be located in the sub-district, arrowband, it is L that length is arranged _b ⁱA ₁Advanced transceiver user in individual broadband and B ₁The basic transceiver user in individual arrowband.Its signal is mapped to respectively $M_0(0<M_0<N_0,0<\underset{i=0}{\mathrm{\&Sigma;}}{L}_b^l\&le;M_0)$ In different sub carrier on.Each subcarrier spacing is bandwidth W ₀Divided by the IFFT length N ₀After IFFT handled, baseband signal can be write as:

$s_l\left(t\right)=\left\{\begin{array}{cc}\frac{1}{\sqrt{T-T_{\mathrm{cp}}}}\underset{i=0}{\overset{A_1+B_1-1}{\mathrm{\&Sigma;}}}\underset{m=0}{\overset{M_0-1}{\mathrm{\&Sigma;}}}{d}_m^i\exp \left[j\frac{2\mathrm{\&pi;}}{N_0}{W}_{0}m(t-T_{\mathrm{cp}})\right]\}& 0\&le;t\&le;T\\ 0& t<0,\mathrm{ort}>T\end{array}---\left(8\right)\right.$

Here T=N ₀/ W ₀+ Tcp is-symbol duration length, Tcp is the Cyclic Prefix duration, M ₀It is available sub-carrier number.Through the transmission of wireless channel, i user (novel transceiver user or basic transceiver user) at the m sub-carrier signal is

$y_m^i=\underset{m\&prime;=0}{\overset{M_0-1}{\mathrm{\&Sigma;}}}{d}_{m\&prime;}^i{\&Integral;}_{T_{\mathrm{cp}}}^T{h}_{m\&prime;}\frac{\exp [j2\mathrm{\&pi;m}\&prime;\frac{W_0}{N_0}(t-T_{\mathrm{cp}})]}{T-T_{\mathrm{cp}}}\exp (-j2\mathrm{\&pi;}\frac{W_0}{N_0}m(t-T_{\mathrm{cp}})\mathrm{dt}+n_m---\left(9\right)$

$=$ $d_m^i{h}_m+n_m$

Wherein the span of narrow-band user transmission subcarrier Coefficient m from 0 to M ₀-1.Corresponding effectively transmission bandwidth is B ₀(B ₀＜W ₀).

Embodiment

1) in the transmission of the novel transceiver subscriber signal of broadband cell

As mobile subscriber MS with novel transceiver ₃And MS ₂When broadband cell transmission data, it is series of symbols b after the coded modulation ³And b ²(length is L _b ³, L _b ²) be mapped to M respectively ₁(0＜M ₁＜N ₁, 0＜L _b ³+ L _b ²≤ M ₁) in different sub carrier.After IFFT handled, the baseband output signal of base station was

$s_l\left(t\right)=\left\{\begin{array}{cc}\frac{1}{\sqrt{T-T_{\mathrm{cp}}}}\left\{\underset{k=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_k^2\exp \right[j\frac{2\mathrm{\&pi;}}{N_1}{W}_{1}k(t-T_{\mathrm{cp}})]+\underset{k=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_k^3\exp [j\frac{2\mathrm{\&pi;}}{N_1}{W}_{1}k(t-T_{\mathrm{cp}})\left]\right\}& 0\&le;t\&le;T\\ 0& t<0\mathrm{ort}>T\end{array}---\left(10\right)\right.$

Here T=N ₁/ W1+Tcp is-symbol the duration, Tcp was a cyclic prefix interval, M at interval ₁Be available sub-carrier number, $d_k^3=b^3{v}_k^3$ With $d_k^2=b^2{v}_k^2,$ v _k ⁱ(as $v_k^i=1,$ Then $v_k^j=0j\&NotEqual;i)$ Represent that k subcarrier is shared by i user.W ₁Be signal bandwidth (as 40MHz),, arrive MS through the transmission (multidiameter fading channel and additive white gaussian noise channels AWGN) of wireless channel ₃And MS ₂Receiver separately.Suppose that each customer parameter can correctly estimate, after removing Cyclic Prefix and analog-to-digital conversion, MS ₃K ofdm signal output signal after handling through FFT is

$y_k^3=\underset{k\&prime;=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_{k\&prime;}^3{\&Integral;}_{T_{\mathrm{cp}}}^T{\&Integral;}_0^{T_{\mathrm{cp}}}h\left(\mathrm{\&tau;}\right)\frac{\exp [j2\mathrm{\&pi;}\frac{W_1}{N_1}k\&prime;(t-\mathrm{\&tau;}-T_{\mathrm{cp}})]}{\sqrt{T-T_{\mathrm{cp}}}}\mathrm{d\&tau;}\frac{\exp [-j2\mathrm{\&pi;}\frac{W_1}{N_1}k](t-T_{\mathrm{cp}})}{\sqrt{T-T_{\mathrm{cp}}}}\mathrm{dt}+n_k$

$=\underset{k\&prime;=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_{k\&prime;}^3{{\&Integral;}_{T_{\mathrm{cp}}}^{T}h}_{k\&prime;}\frac{\exp [j2\mathrm{\&pi;k}\&prime;\frac{W_1}{N_1}(t-T_{\mathrm{cp}})]}{T-T_{\mathrm{cp}}}\exp (-j2\mathrm{\&pi;}\frac{W_1}{N_1}k(t-T_{\mathrm{cp}})\mathrm{dt}+n_k---\left(11\right)$

$=\underset{k\&prime;=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_{k\&prime;}^3{h}_{k\&prime;}\mathrm{\&delta;}(k\&prime;-k)+n_k$

$=d_k^3{h}_k+n_k$

Here $h_{k\&prime;}={\&Integral;}_0^{T_{\mathrm{cp}}}h\left(\mathrm{\&tau;}\right)\exp (-j2\mathrm{\&pi;}\frac{W_1}{N_1}k\&prime;\mathrm{\&tau;})\mathrm{d\&tau;}$ Be the sampling frequency response of channel at frequency domain, $n_k={\&Integral;}_{T_{\mathrm{cp}}}^{T}n\left(t\right)\exp (-j2\mathrm{\&pi;}\frac{W_1}{N_1}\mathrm{kt})\mathrm{dt}$ Be that average is zero Gaussian noise.Correspondingly, the signal that obtains of MS2 is

$y_k^2=d_k^2{h}_k+n_k---\left(12\right)$

Wherein the span of narrow-band user transmission subcarrier Coefficient m from 0 to M ₁-1.Corresponding effectively transmission bandwidth is B ₁(B ₁＜W ₁).

2) in the transmission of the dissimilar subscriber signals of broadband cell

Because arrowband basic transceiver user MS ₀Broadband advanced transceiver user MS with the advanced person ₃Can be operated in different patterns, contain the BTS of advanced transceiver ₁Send respectively and receive two kinds of different signals and MS ₃And MS ₀MS ₀And MS ₃Data to be mapped to length respectively be N ₁(N ₁＞N ₀, N especially ₁=2N ₀) IFFT processor M ₀(0＜M ₀＜N ₀) and M ₁(0＜M ₁＜N ₁) subcarrier on.At the BTS1 transmitting terminal, bandwidth is W ₁The ofdm signal of baseband transmission is:

$s_l\left(t\right)=\left\{\begin{array}{cc}\frac{1}{\sqrt{T-T_{\mathrm{cp}}}}\left\{\underset{m=0}{\overset{M_0-1}{\mathrm{\&Sigma;}}}{d}_m^0\exp \right[j2\mathrm{\&pi;}\frac{W_0}{N_0}m(t-T_{\mathrm{cp}})]+\underset{k=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_k^3\exp [j2\mathrm{\&pi;}\frac{W_1}{N_1}k(t-T_{\mathrm{cp}})\left]\right\}& 0\&le;t\&le;T\\ 0& t<0\mathrm{ort}>T\end{array}---\left(13\right)\right.$

Here, MS ₀Signal is transmitted the scope W of frequency ₀MS ₃The scope that signal is transmitted is W ₁(W ₁＞W ₀).

(W when two users use identical subcarrier spacing ₀/ N ₀=W ₁/ N ₁, 2N especially ₀=N ₁, 2W ₀=W ₁), after inserting the processing of Cyclic Prefix and analog to digital converter, BTS ₁Can use the band pass filter reception in a broadband or the signal of emission different user.The arrangement of subcarrier as shown in Figure 5.Narrow-band user can only use W ₀Green frequency B ₀Part, broadband user's available frequencies scope is frequency band W ₁Blue B ₁Part.Wherein Δ and δ represent the protection sideband of broadband emission frequency spectrum and the protection sideband of narrow emission frequency spectrum respectively.At last, through behind the radio frequency amplifier, this two users' composite signal is transferred out by antenna.

Through wireless channel transmission, MS ₃And MS ₀Receiver carries out filtering to received signal respectively, removes prefix and analog-to-digital conversion process, and FFT processing and demodulation through separately just can access own desired data-signal.

At MS ₀In the receiver, the bandwidth of band pass filter is B ₀, the signal of its FFT output is:

$y_m^0=\underset{m\&prime;=0}{\overset{M_0-1}{\mathrm{\&Sigma;}}}{d}_{m\&prime;}^0{\&Integral;}_{T_{\mathrm{cp}}}^T{h}_{m\&prime;}\frac{\exp [j2\mathrm{\&pi;}\frac{W_0}{N_0}m\&prime;(t-T_{\mathrm{cp}})]}{T-T_{\mathrm{cp}}}\exp (-j2\mathrm{\&pi;}\frac{W_0}{N_0}m(t-T_{\mathrm{cp}})\mathrm{dt}+n_m---\left(14\right)$

$=d_m^0{h}_m+n_m$

Wherein the span of m from 0 to M ₀-1, available transmission bandwidth is B ₀

And at MS ₃In the receiver, the bandwidth of band pass filter is W ₁, its FFT is output as

$y_k^3=\underset{k\&prime;=0}{\overset{M_1-1}{\mathrm{\&Sigma;}}}{d}_{k\&prime;}^3{\&Integral;}_{T_{\mathrm{cp}}}^T{h}_{k\&prime;}\frac{\exp [j2\mathrm{\&pi;}\frac{W_1}{N_1}k\&prime;(t-T_{\mathrm{cp}})}{T-T_{\mathrm{cp}}}\exp (-j2\mathrm{\&pi;}\frac{W_1}{N_1}k(t-T_{\mathrm{cp}})\mathrm{dt}+n_k---\left(15\right)$

$=d_k^3{h}_k+n_k$

Wherein the span of m from 0 to M ₁-1, available transmission bandwidth is B ₁

3) transmit at the arrowband cell signal

When having two users to transmit data in the sub-district, arrowband, one is narrowband terminal MS ₀With one be wide-band terminal MS ₁, the base station BTS of arrowband ₀Adopt N ₀Point IFFT/FFT processor is communicated by letter with it.These two users use the blue portion transmission signals of Fig. 5.

After IFFT handled, the baseband signal of its output was

$s_l\left(t\right)=\left\{\begin{array}{cc}\frac{1}{\sqrt{T-T_{\mathrm{cp}}}}\left\{\underset{m=0}{\overset{M_0-1}{\mathrm{\&Sigma;}}}{d}_m^i\exp \right[j\frac{2\mathrm{\&pi;}}{N_0}{W}_{0}m(t-T_{\mathrm{cp}})\left]\right\}& 0\&le;t\&le;T\\ 0& t<0,\mathrm{ort}>T\end{array}---\left(16\right)\right.$

Here i ∈ (0,1) expression i user.Baseband output signal is finished the Cyclic Prefix insertion, and (centre frequency is f for analog-to-digital conversion and frequency translation ₀) after, transmitting antenna sends this signal.

At receiving terminal, two users' narrow band filter (W ₀) receive the signal of base station.By fft processor separately, MS ₀And MS ₁The signal that obtains demodulation respectively is output as

$y_m^0=\underset{m\&prime;=0}{\overset{M_0-1}{\mathrm{\&Sigma;}}}{d}_{m\&prime;}^0{\&Integral;}_{T_{\mathrm{cp}}}^T{h}_{m\&prime;}\frac{\exp [j2\mathrm{\&pi;}\frac{W_0}{N_0}m\&prime;(t-T_{\mathrm{cp}})}{T-T_{\mathrm{cp}}}\exp (-j2\mathrm{\&pi;}\frac{W_0}{N_0}m(t-T_{\mathrm{cp}})\mathrm{dt}+n_m---\left(17\right)$

$=d_m^0{h}_m+n_m$

$y_m^1=d_m^1{h}_m+n_m---\left(18\right)$

Here the m span is to M from 0 ₀-1.The summation of two users' available subcarrier is M ₀, available transmission bandwidth is B ₀

The present invention applies to the novel scalable transceiver of wide-band mobile communication system with software and radio technique, makes broadband travelling carriage and arrowband travelling carriage access base station system effectively.The present invention makes subcarrier spacing keep identical in different system.In broadband cell, the parameter of each community user such as following table,

At broadband cell broadband mobile subscriber and arrowband mobile subscriber's transceiver parameter comparison table

Table 1 broadband cell transmission parameter MS type	Transmission bandwidth	The FFT size	Δf	Available bandwidth	Available sub-carrier number	The protection frequency band	Symbol lengths (T)
								Novel MS	W 1	N 1	W 1/N 1	B 1	M 1	2Δ	W 1/N 1+ Tcp
Basic MS	W 0	N 0	W 0/N 0	B 0	M 0	2	W 0/N 0+ Tcp

Its parameter is as follows:

The broadband has identical subcarrier: W with narrowband terminal with system ₀/ N ₀=W ₁/ N ₁

The broadband has identical OFDM symbol period: T with narrowband terminal with system;

Wide-band terminal has different sub-carrier numbers: M with narrowband terminal ₁And M ₀

Wide-band terminal has different available spectrum scopes: B with narrowband terminal ₁And B ₀

Wide-band terminal uses protection frequency band (although the subcarrier that system can use is identical in the position of frequency band) inequality with narrowband terminal: Δ and δ.

In the sub-district, arrowband, the parameter of each community user such as following table.

At sub-district, arrowband broadband mobile subscriber and arrowband mobile subscriber's transceiver parameter comparison table

The MS type	Transmission bandwidth	The FFT size	Δf	Available bandwidth	Available sub-carrier number	The protection bandwidth	Mark space (T)
								Novel MS	W 0	N 0	W 0/N 0	B 0	M 0	2	W 0/N 0+ Tcp
Basic MS	W 0	N 0	W 0/N 0	B 0	M 0	2	W 0/N 0+ Tcp

The broadband has identical subcarrier: W with narrowband terminal ₀/ N ₀=W ₁/ N ₁

The broadband has identical OFDM symbol period: T with narrowband terminal;

Identical sub-carrier number: M is used with narrowband terminal in the broadband ₀

The broadband is consistent with narrowband terminal available spectrum scope: B ₀

The broadband keeps identical protection frequency band: δ with narrowband terminal.

Based on the novel transceiver IFFT/FFT module bandwidth efficiency of software wireless electric control than higher.Bandwidth efficiency is an index describing its characteristic.Bandwidth efficiency is represented the bit-rate that transmits under the per unit bandwidth.When using OFDM transmission M system modulating data, its bandwidth efficiency is log ₂Mbits/s/Hz.To given serial data stream character rate is l/T _s, corresponding M system bandwidth efficiency is log ₂M/T _s. the transmission bandwidth efficiency is log on each subcarrier ₂M/ (M _iT _s) .M _iIt is available sub-carrier number.So, the whole bandwidth of OFDM is

$W_i=B_i+2f_g^i---\left(19\right)$

Here f _g ⁱBe in order to isolate the required protection frequency band of adjacent wireless signal.Adopt the resulting maximum band efficient of the present invention to be:

${\mathrm{\&eta;}}_2=\frac{{\log }_{2}M}{1+\mathrm{\&Delta;}/M_1}$

The present invention has realized a kind of new scalable transceiver architecture by software and radio technique.It can be applied to wide bandwidth base station and broadband travelling carriage neatly.

If this new transceiver of software radio controller structure is adopted in the base station; Just can come the control system module parameter according to the travelling carriage type.These parameters comprise the band pass filter bandwidth, and the IFFT/FFT subcarrier is counted, modulation and demodulation pattern, coding and type of deciphering and parameter etc.And the enough IFFT processing apparatus of energy are realized the transmission conversion of unlike signal; Realize the receiving conversion of different in width signal with a FTT processing apparatus.

If travelling carriage adopts software radio controller structure advanced person's transceiver; Just can control and adjust its system module parameter according to base station type and order.These parameters comprise the band pass filter bandwidth, and the IFFT/FFT subcarrier is counted, modulation and demodulation pattern, coding and type of deciphering and parameter etc.The channel configuration controller can reasonably be assigned subcarrier for various users according to the instruction of software wireless electric controller.

In a word, by to the analysis of scalable transceiver with studies show that: have back compatible characteristic and variable element characteristic based on base station of the present invention and mobile station system, be easy to the smooth upgrade of system and terminal and control flexibly.Simultaneously, the present invention is simple in structure, is similar to traditional ofdm system structure, realizes that in base station and travelling carriage cost is lower.

Claims (13)

1. one kind based on the upgradeable OFDM base station transceiver of software radio, it is characterized in that:

The emission system of changeable mode;

The receiving system of changeable mode;

The software wireless electric controller is used for controlling respectively each module and the parameter setting thereof of emission system and receiving system;

The channel allocation controller is for each user assigns corresponding subcarrier.

2. transceiver according to claim 1 is characterized in that: the emission system of described changeable mode comprises:

The Adaptive Modulation and Coding module is used for modulation and coding mode, and multiple modulation and coding can supply and carry out adaptively selected;

String and modular converter are used for converting the serial signal after the modulation to parallel signal;

Sub-district spread spectrum and scrambling module are used for that the signal after going here and there is also carried out spread spectrum and scrambling is handled, and spread spectrum length is pressed the peripheral cell recycling rate of waterused and determined the employed frequency expansion sequence difference in each sub-district;

The IFFT conversion process module of variable-length is used for the signal behind the spread spectrum is carried out quick inverse-Fourier transform (IFFT), and its transform length can be carried out conversion as required;

The software wireless electric control module, each module and the parameter setting thereof that are used to dispose emission system;

The channel allocation control module is for each user assigns corresponding subcarrier;

The parallel signal that parallel serial conversion module, IFFT are handled the back different frequent points converts serial signal to;

The Cyclic Prefix insert module is inserted its front portion at each OFDM symbol rear portion signal, is used to eliminate intersymbol interference;

D/A converter module is carried out analog-to-digital conversion with the signal that has added Cyclic Prefix;

The band pass filter module of bandwidth varying will be finished analog-to-digital signal and be transformed into intermediate-freuqncy signal from fundamental frequency signal, and its passband width is variable;

Radio frequency amplifier and transmitting antenna module are adjusted to signal the frequency range of expectation emission and are launched behind feed antenna.

3. transceiver according to claim 1 is characterized in that described receiving system comprises:

The adaptive demodulation decoding module; Be used for modulation and coding mode, multiple modulation and coding can supply and carry out adaptively selected;

Radio-frequency filter and reception antenna module, antenna receives desired radiofrequency signal in corresponding frequency range;

The alterable band-pass filter module, bandpass filtering to received signal, its passband width is variable;

Cyclic Prefix is removed module, removes Cyclic Prefix in time-domain, allows pure OFDM symbol export;

Analog-to-digital conversion module becomes digital signal with analog signal conversion;

String and modular converter convert serial signal to parallel signal, so that carry out parallel processing;

Sub-district despreading and descrambling module carry out despreading and scramble process with spread spectrum and scrambled signals, recover former transmission signals;

Variable-length FFT conversion process module is carried out fast fourier transform with input signal, and treated length is variable;

The channel configuration controller module; For each user assigns corresponding subcarrier;

The software radio controller module is used to control each module and the parameter setting thereof of receiving system;

Parallel serial conversion module, the parallel signal of different frequent points converts serial signal to.

4. transceiver according to claim 1 is characterized in that described base station transceiver function is supported in narrow band bandwidth or broader frequency spectrum transmission signals.

5. method according to claim 4 is characterized in that described transceiver comprises following system parameters:

The broadband has identical subcarrier: W with narrowband systems ₀/ N ₀=W ₁/ N ₁

The broadband has identical OFDM symbol period: T with narrowband systems;

The broadband has different sub-carrier numbers: M with narrowband systems ₁And M ₀

The broadband has different available spectrum scopes: B with narrowband systems ₁And B ₀

The broadband has different protection frequency bands with narrowband systems: Δ and δ.

6. transceiver according to claim 1 is characterized in that described software radio controller module controls each module and the parameter setting of emission system and receiving system respectively and comprise:

The software wireless electric controller is accepted the top signaling indication, knows user waiting for transmission and channel characteristics thereof;

Software wireless electric controller control Adaptive Modulation and Coding module, channel configuration controller, transmit band pass filter pattern and parameter, radio frequency amplifier parameter;

Software wireless electric controller control adaptive demodulation decoding module, channel configuration controller, reception bandpass filter (BPF) pattern and parameter, radio-frequency filter parameter.

7. transceiver according to claim 1 is characterized in that described channel allocation controller comprises for each user assigns subcarrier:

The channel allocation controller is accepted the control signal from the software wireless electric controller, obtains each mobile subscriber and base station characteristic information;

The channel allocation controller is according to each user's transmitting channel information and out of Memory, for it assigns corresponding transmission subcarrier;

Each subcarrier energy of assigning by the channel allocation controller and to the greatest extent can be shared by a user;

For a user, the channel allocation controller of transmitting terminal and receiving terminal assigns subcarrier to be consistent.

8. transceiver according to claim 1 is characterized in that the parameter of described software wireless electric controller comprises:

Software wireless electric controller control band pass filter bandwidth, center frequency point;

The scope of software wireless electric controller control IFFT/FFT module variable sub carriers number: M ₁And M ₀

Software wireless electric controller control Adaptive Modulation and Coding and demodulation decoding mode.

9. according to claim 2 or 3 described transceivers, it is characterized in that:

The band pass filter bandwidth can be adjusted the bandwidth broadband according to software wireless electric controller control command;

In broadband cell, the band pass filter of base station transmitter and the band pass filter of receiver can be inconsistent;

In broadband cell, the band pass filter of the transmitter of travelling carriage and the band pass filter of receiver also can be inconsistent, can be arranged to broadband or arrowband according to system command;

In the sub-district, arrowband, the band pass filter of travelling carriage transmitter and the band pass filter of receiver all must be arranged to the arrowband.

10. according to claim 2 or 3 described transceivers, it is characterized in that:

The IFFT/FFT processor can be adjusted treated length according to the SRC control command;

For narrow-band user in the broadband cell, the base station is provided with less number: N with its corresponding IFFT/FFT treated length ₀

For broadband user in broadband cell, the treated length of IFFT/FFT processor can be provided with bigger number: N ₁

In the sub-district, arrowband, travelling carriage IFFT/FFT treated length is provided with less number: N ₀

11., it is characterized in that according to claim 2 or 3 described transceivers:

Adaptive Modulation and Coding device module realizes multiple modulation and coding form according to the order of software wireless electric controller;

The pattern of modulation has BPSK, QPSK, 8PSK, 16QAM, 64QAM, 256QAM;

Coding mode has convolution code and Turbo code.

12. according to claim 1,4 or 5 described transceivers; it is characterized in that: in broadband cell; though wide-band terminal and narrowband terminal are used the width of available band inequality and protection frequency band, system and terminal can with subcarrier be identical in the frequency domain original position.

13. according to claim 1,4 or 5 described transceivers, it is characterized in that: in the sub-district, arrowband, the transmission bandwidth of broadband and narrowband terminal all is identical with protection frequency band and available subcarrier in the frequency domain original position.

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