CN1561594A - Method and apparatus for spread space time block coding - Google Patents

Method and apparatus for spread space time block coding Download PDF

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Publication number
CN1561594A
CN1561594A CN02819179.XA CN02819179A CN1561594A CN 1561594 A CN1561594 A CN 1561594A CN 02819179 A CN02819179 A CN 02819179A CN 1561594 A CN1561594 A CN 1561594A
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code
symbol
block code
reception
antenna
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李轶
李永会
张永生
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Linkair Communications Inc
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Linkair Communications Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J13/00—Code division multiplex systems
    • H04J13/10—Code generation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J13/00—Code division multiplex systems
    • H04J13/16—Code allocation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/02—Arrangements for detecting or preventing errors in the information received by diversity reception
    • H04L1/06—Arrangements for detecting or preventing errors in the information received by diversity reception using space diversity
    • H04L1/0618—Space-time coding

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
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Abstract

The present invention relates to a method and apparatus of spread space-time block coding. The method comprises the steps of space-time block coding input bits by a transmission side; converting the input bits into symbols and modulating said symbols; serial-parallel converting and channel interleaving the modulated symbols; transmitting the final symbols by at least two transmitting antennas; receiving the signal from said antennas by a receiving antenna at a receipt side; and processing the received signal. The present invention make any of block code with a rate of 1/N (such as different liner and non-liner block codes) be used in a system with N transmitting antennas. When using block codes with a long constraint length, we can obtain a greater coding gain than the conventional space-time block coding.

Description

Method and apparatus for spread space time block coding
A kind of space-time block code coding method of extension and device
Technical field the present invention relates to communication technical field, concretely its be a kind of extension Shi Kong Fen Group code encoding methods and device.Background technology
It is well known that in fading channel, the decline of signal is by the performance of severe exacerbation system.It is to use diversity technique to overcome the maximally effective means of decline.It will be seen that Space-time coding techniques can obtain diversity gain and coding gain simultaneously in bibliography [1], [2] and [3], and the influence of decline can be overcome, improve the reliability of transmission.
Particularly we can learn in bibliography [1], [2], although space-time block code results in full diversity gains and has the characteristics of decoding simple, but it can not obtain sufficiently large coding gain, even if multi-mode space-time Trel l i s codes（Space-time grid code）, can be obtained coding gain also very limited.Therefore, how the problem of sufficiently large coding gain is become to need to solve can also be obtained while full diversity gains are obtained.The content of the invention
It is an object of the present invention to provide a kind of space-time block code coding method of extension and device so that any code check Wei Shang block code (including various linear Fen Group codes and nonlinear packet
N
Code）It may be used to the system with N number of transmitting antenna.When the block code using long constraint length, the coding gain bigger than traditional space-time block code can be obtained.
The technical scheme is that：The space-time block code coding method of a kind of extension, it is characterised in that transmitting terminal carries out block code coding to input bit, it is symbol by the bits switch after coding, described symbol is modulated, the symbol after modulation serioparallel exchange and channel interleaving is subjected to, at least using two Individual transmitting antenna launches the symbol after serioparallel exchange and channel interleaving；
Receiving terminal at least receives the signal transmitted from transmitting antenna using a reception antenna, and carries out reception processing to the signal of reception.
Described transmitting terminal, which carries out block code coding to input bit, to be included：The block code that uses of block code coding can be any code check for 1/N block code, the code word of the block code, which is generated, need to meet following condition：D=b. Ge e, D are one, and b is input information, and G is generator matrix, and e is an offset.
Described be modulated described symbol refers to：Described symbol can be modulated using Different Modulations such as QPSK.
Described at least launched the symbol after serioparallel exchange and channel interleaving using two emitting antennas is referred to：The symbol after serioparallel exchange and channel interleaving can be launched using N transmitting antenna, N is more than or equal to 2 here.
Described receiving terminal is at least received the signal transmitted from transmitting antenna using a reception antenna and referred to：Receiving terminal can receive the signal transmitted from transmitting antenna using M reception antenna, and M is more than or equal to 1 here.
Described receiving terminal carries out reception processing to the signal of reception and referred to：Receiving terminal at least carries out block code decoding to the signal of reception.
A kind of space-time block code coding method of described extension, Qi Bu Sudden include：
Transmitting terminal：Carry out block code coding to input bit, the block code that uses of block code coding can be any code check for 1/N block code, the code word of the block code, which is generated, need to meet following condition：
D=b Ge e, D are that a b is input information, and G is generator matrix, and e is an offset；
It is symbol by the bits switch after coding；
Described symbol can be modulated using Different Modulations such as QPSK；
Symbol after modulation is subjected to serioparallel exchange and channel interleaving；
The symbol generated after channel interleaving can be launched using N number of transmitting antenna, N is more than here Equal to 2;
Receiving terminal：The signal transmitted from transmitting antenna can be received using M reception antenna, M is more than or equal to 1 here;
Block code decoding is at least carried out to the signal of reception, described decoding can be using a variety of decodings such as maximum-likelihood decodings.
Described code check includes for 1/N block code：Various linear Fen Group codes and nonlinear block code.
A kind of its step of the space-time block code coding method of described extension can further include：Transmitting terminal：To input bit bl3 b2, bn/2Carry out (n, n/2) block code coding；By the bit d after coding2..., dnBe converted to symbolCl, c2, ...,cn/2;
Described symbol can be modulated using QPSK modulation, n/ complex signal x of output after this n/2 symbol is modulatedl5 x2, ·.·, xn/2;
These complex signals are launched after serioparallel exchange and channel interleaving from two emitting antennas, wherein preceding n/4 complex signal xl5 x2..., xn/4Channel interweaves to be launched from an antenna, rear n/4 complex signal xn/4+1, xn/4+2..., xn/2Channel interweaves to be launched from another antenna;
Receiving terminal：The signal transmitted from transmitting antenna can be received using 1 reception antenna or multiple reception antennas, receiving n/4 reception signal is：
= hn * Xj + h2i * xiW4 + Vi i=l, 2,..., n/4
Due to（N, n/2) block code codeword set in have 2n/2Individual code word, so for any one code word Ck, it has n bit, ' n/2 complex signal ^ L is transformed into after conversion of this n bit through described bit to symbol and QPSK modulationx/2;
^ mouthfuls of fruit ∑s-' χ " χί+η/4 ≤∑ - 'x -h2i.x J i+nn/4
=1
Vje tl, 2n/2] j≠k
So maximum-likelihood decoding output codons are code word ck。
Present invention also offers a kind of space-time block code code device of extension, including： Emitter and reception device；
Described emitter is made up of block coder, bits switch for conversion equipment, modulator, serioparallel exchange device, channel interleaver and at least two transmitting antennas of symbol；
Described reception device at least includes packet code decoder and at least one reception antenna.
The Fen Group code coders are：Can to any code check for 1/N's and code word generation meet the encoder that D=b. G e block code is encoded.
Described modulator can use qpsk modulator, and other modulators.
At least two described transmitting antennas refer to：N number of transmitting antenna, N is more than or equal to 2 here.At least one described reception antenna refers to：M reception antenna, M is more than or equal to 1 here.The Fen Group code decoders refer to：A variety of decoders can be used, the packet code decoder of maximum-likelihood decoding can be at least used.
A kind of space-time block code code device of described extension, it is characterised in that
Described emitter is by that can be 1/N's to any code check and code word generation meets conversion equipment, qpsk modulator, serioparallel exchange device, channel interleaver and N number of transmitting antenna that block coder, the bits switch that D=b. Ge e block code encoded are symbol and constituted, and N is more than or equal to 2 here;
Described reception device at least includes the packet code decoder and M reception antenna using maximum-likelihood decoding, and M is more than or equal to 1 here.The beneficial effects of the present invention are：The present invention makes the block code that any code check is 1/N（Including various linear block codes and nonlinear block code) it may be used to the system with N number of transmitting antenna.When the block code using long constraint length, the coding gain bigger than traditional space-time block code can be obtained.So as to achieve the good result of sufficiently large coding gain can also be obtained while full diversity gains are obtained.Brief description of the drawings
Fig. 1 is traditional space-time block code method block diagram using one reception antenna of two emitting antennas； Fig. 2 is QPSK modulation constellations；
Fig. 3 is the coding block diagram of traditional space-time block code using two emitting antennas；
Fig. 4 is the ^ I figures with the extension Shi Kong Fen Group code methods of traditional space-time block code equivalence using two emitting antennas；
Fig. 5 be the specific embodiment of the invention in using one reception antenna of two emitting antennas using QPSK modulate extension space-time block code block diagram；
Fig. 6 is simulation curve of the invention.
Embodiment
For the ease of describing, we illustrate by taking one reception antenna of two emitting antennas and QPSK modulation as an example herein, and it can be generalized to the multiple reception antennas of multiple transmitting antennas and other modulation schemes.
Here traditional space-time block code method is first introduced：
It is to use one reception antenna of two emitting antennas, the traditional space-time block code method modulated using QPSK as shown in Figure 1.Input bit is first converted into symbol, and these symbols are modulated, and two after modulation continuous symbol is designated as xl x2, in a symbol period, x^ x2Launch simultaneously from antenna 1 and antenna 2 respectively, in next symbol period ,-and j；Launch simultaneously from antenna 1 and antenna 2 respectively.Assuming that the channel fading between t, transmitting antenna 1 and reception antenna is designated as（T), the channel fading between transmitting antenna 1 and reception antenna is designated as h2(t) signal that, reception antenna is received is designated as r (t), receives signal and is disturbed by white Gaussian noise, the power spectral density of noise is designated as C72=N./2 .So have：
r (t) = (t) Xj + h2 (t) x2 + vt
r (t+T) = (t+T) (_ ；) + h2 (t+T) χ1+ vt+T(1) concept below to above-mentioned space-time block code is extended. It is assumed that QPSK modulation used in Fig. 1 is as shown in Figure 1.
Space-time block code coding in Fig. 1 is separated as shown in Figure 3.
A kind of space-time block code ESTBC (extended space-t ime block codes) of the extension of equal value with traditional space-time block code using two emitting antennas coding method is given below as shown in Fig. 4.
Block Code in Fig. 4 are a block coders.The block code that Block Code encoders in Fig. 4 are used is the block code of 1/2 code check, and the code word create-rule of the block code is：
Figure IMGF000008_0001
Wherein D=(dl3 d2..., d8) is a code word, it is made up of 8 bitsc b = (bl5 b2, b3, b4) it is input information bits, it is made up of 4 bits.
Figure IMGF000008_0002
It is generator matrix.
Figure IMGF000008_0003
E is an offset.
16 code words are so had in the codeword set of the block code.
Can verify, it is assumed that the Block Code encoders in Fig. 4 be according to（2)、
Formula is generated during code word, this extension described by Fig. 4 when, code and traditional space-time block code described by Fig. 3 are equivalents.It can be said that traditional Shi Kong Fen Group codes described by Fig. 3 are a kind of special cases of the Shi Kong Fen Group codes of this extension described by Fig. 4, Fig. 4 is a kind of broad sense Space-time block code.
The advantage of the space-time block code of this extension shown in Fig. 4 is that its code word design is more flexible, and when using N number of transmitting antenna, Block Code therein can be the group code of any 1/N code checks, code gain.Here it is by taking two emitting antennas as an example, so with the block code of 1/2 code check.Fig. 5 is the extension space-time block code scheme using one reception antenna of two emitting antennas.Decoding on the space-time block code of this extension can have a variety of methods, and a kind of maximum-likelihood decoding algorithm is provided here.
It is described as follows corresponding to the maximum-likelihood decoding algorithm of the ESTBC shown in Fig. 5：
In Figure 5, η/2 input bit passes through (η, η bit is exported after the block code of η/2) coding, this η bit is a code word, because being so that QPSK is modulated as an example here, so two, bits switch are into a symbol, this η bits switch is into η/2 symbol, output η/2 complex signal after this η/2 symbol is modulated, these complex signals are launched after serioparallel exchange from two emitting antennas, wherein preceding n/4 complex signal is launched from antenna 1, and rear n/4 complex signal is launched from antenna 1.Receiving n/4 reception signal in receiving terminal is：
Figure IMGF000009_0001
2 are had in the codeword set of (n, n/2) block coden/2Individual code word.For any one code word Ck, it has n bit, and this n bit is through in Fig. 5 " bit to symbol conversion, and n/2 complex signal ^, v, are transformed into after " QPSK modulation ", if j
Xi+n
Figure IMGF000009_0002
V j e [l, 2n/2] j≠k (6)
So maximum-likelihood decoding output codons are code word Ck Fig. 6 is to extend space-time block code using bit error rate performance curve during several different block codes, and the algorithm used is the maximum-likelihood decoding algorithm above provided.Simulation parameter is as shown in table 1.
Table 1:Simulation parameter table
Figure IMGF000010_0001
It can be seen that, the present invention makes the block code that any code check is 1/N（Including various linear Fen Group codes and nonlinear block code）It may be used to the system with N number of transmitting antenna.When the block code using long constraint length, the coding gain bigger than traditional space-time block code can be obtained.So as to achieve the good result of sufficiently large coding gain can also be obtained while full diversity gains are obtained.
Above embodiment is merely to illustrate the present invention, of the invention not for limiting.
The bibliography of the present invention:
[1] Siavash M. Alamouti, "A simple Transmit Diversity Technique for Wireless Communications," IEEE Journal on select areas in communications. Vol. 16. NO.8, October 1998.
[2] Vahid Tarokh, Hamid Jafarkhani and A. Robert Calderbank, "Space-Time Block Coding for Wireless Communications:Performance Results, ', IEEE Journal on select areas in communications. Vol. 17. N0.3, March 1999.
[3] V. Tarokh, N. Seshadri, and A. R. Calderbank, "Space-Time Codes for High Data Rate Wireless Communication: Performance Criterion and Code Construction," IEEE Trans. IT, 44(2): 744-765, Mar. 1998.

Claims (16)

  1. Claim
    1. a kind of space-time block code coding method of extension, it is characterized in that, transmitting terminal carries out block code coding to input bit, it is symbol by the bits switch after coding, described symbol is modulated, symbol after modulation is subjected to serioparallel exchange, then by channel interleaving, at least launched the symbol after channel interleaving using two emitting antennas；
    Receiving terminal at least receives the signal transmitted from transmitting antenna using a reception antenna, and carries out reception processing to the signal of reception.
    2. according to the method described in claim 1, it is characterised in that described transmitting terminal, which carries out block code coding to input bit, to be included：The block code that uses of block code coding can be any code check for 1/N Fen Group codes, the code word of the block code, which is generated, need to meet following condition：D=b G e, D are that a b is defeated Arf speeches breath bit, and G is generator matrix, and e is an offset.
    3. according to the method described in claim 1, it is characterised in that described be modulated described symbol refers to：Described symbol can be modulated using Different Modulations such as QPSK.
    4. according to the method described in claim 1, it is characterised in that described at least launched the symbol after channel interleaving using two emitting antennas is referred to：The symbol after channel interleaving can be launched using N transmitting antenna, N is more than or equal to 2 here.
    5. according to the method described in claim 1, it is characterised in that described receiving terminal is at least received the signal transmitted from transmitting antenna using a reception antenna and referred to：Receiving terminal can receive the signal transmitted from transmitting antenna using M reception antenna, and M is more than or equal to 1 here.
    6. according to the method described in claim 1, it is characterised in that described receiving terminal carries out reception processing to the signal of reception and referred to：Receiving terminal at least carries out block code decoding to the signal of reception.
    7. according to the method described in claim 1, its step includes：
    Transmitting terminal：Carry out block code coding to input bit, the block code that uses of block code coding can be any code check for 1/N block code, the code word of the block code, which is generated, need to meet following condition：D=b- Ge e, D are one, and b is that input information G is generator matrix, and e is an offset； It is symbol by the bits switch after coding；
    Described symbol can be modulated using Different Modulations such as QPSK；
    Symbol after modulation is subjected to serioparallel exchange and channel interleaving；
    The symbol after channel interleaving can be launched using N number of transmitting antenna, N is more than or equal to 2 here;Receiving terminal：The signal transmitted from transmitting antenna can be received using M reception antenna, M is more than or equal to 1 here;
    Block code decoding is at least carried out to the signal of reception, described decoding can be using a variety of decodings such as maximum-likelihood decodings.
    8. method according to claim 7, it is characterised in that described code check includes for 1/N block code：Various linear block codes and nonlinear block code.
    9. method according to claim 7, its step further comprises：
    Transmitting terminal：To input bit b1; b2, bn/2Carry out (n, n/2) block code coding；By bit (^, the d after coding2, dnBe converted to symbolCl,c2..., cn/2;
    Described symbol can be modulated using QPSK modulation, n/2 complex signal x of output after this n/2 symbol is modulatedl5 x2, .·., xn/2;These complex signals are launched after serioparallel exchange and channel interleaving from two emitting antennas, wherein preceding n/4 complex signalXl, x2, ...,xn/4Channel is launched after interweaving from an antenna, rear n/4 complex signal xn/4+1, xn/4+2..., xn/2Channel is launched after interweaving from another antenna；Receiving terminal：The signal transmitted from transmitting antenna can be received using 1 reception antenna, receiving n/4 reception signal is：
    Γι = hH * Xi + h2i * xi¾/4 + Vi i=l, 2,..., n/4
    Due to（N, n/2) block code codeword set in have 2n/2Individual code word, so for any one code word Ck, it has n bit, is transformed into n/2 complex signal after conversion of this n bit through described bit to symbol and QPSK modulation, ^ ...,x k n/2;
    «/4| 2 "/4| · .
    If ∑ ';.- ≤∑ - -Xi -h2i-x+"/4
    i=l /=1 V j e [1, 2n/2j j≠k
    So maximum-likelihood decoding output codons are code word ck。
    10. a kind of space-time block code code device of extension, including：
    Emitter and reception device；
    Described emitter is made up of block coder, bits switch for conversion equipment, modulator, serioparallel exchange device, channel interleaver and at least two transmitting antennas of symbol；
    Described reception device at least includes packet code decoder and at least one reception antenna.
    11. device according to claim 10, it is characterised in that described block coder is：Can to any code check for 1/N's and code word generation meet the encoder that D=b. G e block code is encoded.
    12. device according to claim 10, it is characterised in that described modulator can use qpsk modulator and other modulators.
    13. device according to claim 10, it is characterised in that at least two described transmitting antennas refer to:N number of transmitting antenna, N is more than or equal to 2 here.
    14. device according to claim 10, it is characterised in that at least one described reception antenna refers to：M reception antenna, M is more than or equal to 1 here.
    15. device according to claim 10, it is characterised in that described packet code decoder refers to：A variety of decoders can be used, the packet code decoder of maximum-likelihood decoding can be at least used.
    16. device according to claim 10, it is characterised in that
    Described emitter by can to any code check for 1/N's and code word generation meet
    Block coder, the conversion equipment that bits switch is symbol, qpsk modulator, serioparallel exchange device, channel interleaver and the N number of transmitting antenna that D=b. Ge e block code is encoded are constituted, and N is more than or equal to 2 here;
    Described reception device at least includes the packet code decoder and M reception antenna using maximum-likelihood decoding, and M is more than or equal to 1 here.
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