Device and method for finding optimal modulation process in communication system

FIELD: communication systems using variable transfer process; optimizing modulation process and code repetition frequency in given hardware environment.

SUBSTANCE: in order to find most effective modulation and code repetition frequency process including code correction according to this criterion, communication system transmitter is provided with code packet coder and certain set of modulators having different modulation orders and modulating sub-packets that function as code words outputted from coder. Selector functions to select one of modulators by comparing product of modulation order by code repetition frequency which is, essentially, relationship between code packet size and number of information modulating characters and by comparing product of modulation order by code repetition frequency with threshold value.

EFFECT: enhanced effectiveness of found process.

29 cl, 6 dwg, 1 tbl

 

The technical field to which the invention relates.

This invention in General relates to a communication system using the method of transmission, and in particular to a device and method for determining an optimal transmission method, and a repetition frequency of codes in a given hardware environment.

The level of technology

Although conventional communication system uses a fixed data transfer method, but by now developed a technique to transfer the data in accordance with a variable transmission method. For example, the mobile communication system of the new generation developed by 3GPP2, SPP (2nd Joint Project of the 3rd Generation), applies variable transmission method.

Presented by L3QS (Lucent Technology Co., LSI Co., LG Electronics, Qualcomm Co., Samsung Electronis Co.) the basic proposal, which was included in the working group TSG-C WG5 Project SPP in June 2000 for standardization standard 1x EV-DV (1x Evolution-Data and Voice), developed by the Project SPP, is a compilation of data rates for the six dimensions modernage package KP (i.e. 384, 768, 1536, 2304, 3072 and 3840 bits) in six tables. These tables of data transfer rate designed to increase the utilization of the transmission channel by providing a set of packets at any given moment. KP is a package entered in the encoder. You must choose according to stuudy size KP from among the six dimensions KP in accordance with the state of the channel, unfinished tasks on the data (i.e. the status of the buffer memory devices having data from more upper level) and in accordance with the number of available Walsh codes (CHICK). One of the important factors when choosing the size of the CP is the choice of modulation method. For example, for packets with the same amount of CP you can apply different methods of modulation and different frequency codes with error correction depending on their duration of transmission, and CHICK.

Each table speed data transfers from 69 to 111 different combinations of modulation and repetition frequency codes in accordance with the number of available Walsh codes (CHICK) and the number of time intervals based on one subpacket. For example, if the size of the CP=384, CHICK,=28, and the number of time intervals TWI=8, the order of modulation=2 (quadrature phase shift keying (FMC)and the repetition rate codes=0,017857. If the size of the CP=384, CHICK,=27, and TWI=8, the order of modulation=2 (CPM), and repetition rate codes=0,037037. It is therefore very important to choose the optimum modulation method and the frequency of codes in this hardware environment in the communication system using variable in time transfer method.

The invention

Therefore, the objective of this invention is to provide a selection of adaptive modulation and coding (AMC) and the creation of the device and the person determine the most effective method of modulation and repetition rate codes with error correction on the basis of this criterion.

To solve this task and other tasks in the communication system using variable transmission method, an apparatus and method for determining an optimum modulation method and the optimal repetition rate codes. The transmitter of the communication system, the encoder encodes moderny package (KP), with some combination of modulators with different orders of modulation modulates subpacket, which code words output from the encoder. The selector selects one of the modulators by comparing the works order modulation frequency code (PMCS), which is the ratio of the size of the CP and the number of information modulation symbols, and by comparing PMCS with some threshold value.

Brief description of drawings

These and other objectives, features and advantages of this invention will become more apparent from the following detailed description in conjunction with the accompanying drawings, on which:

Figure 1 illustrates three lines pointing Ec/Nt (dB)required to provide 1% kopek PMCS in the FMC, 8-MFN (phase shift keying) and 16-QAM (quadrature amplitude modulation), if the size of the CP is 384 bits;

Figure 2 illustrates three lines pointing Ec/Nt (dB)required to provide 1% kopek PMCS in the FMC, 8-MFN and 16-QAM, if the size of the CP is 1536 bits

Figure 3 illustrates three lines pointing Ec/Nt (dB)required to provide 1% kopek PMCS in the FMC, 8-MFN and 16-QAM, if the size of the CP is 3072 bits;

4 is a flowchart illustrating a method of modulation that determines the procedure in accordance with one embodiments of the present invention;

5 is a block diagram of a device that selects the modulator, in accordance with one embodiments of the present invention;

6 is a block diagram of a device that selects the demodulator, in accordance with one embodiments of the present invention.

Detailed description of the preferred embodiment of the

The preferred description of the invention is described below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail so as not to overload the invention with unnecessary details.

The description is a consideration of the relationship between each data rate and modulation method/frequency of repetition codes - criterion for determining the optimal order modulation; and selecting the modulation method (or order modulation)/repetition rate codes according to this criterion. According to a variant implementation of the invention, the work order modulation frequency codes (PMCS) Yes what about as a criterion of choice of the method of modulation/frequency of repetition codes. Therefore, as will be described calculation PMCS and method and device for selecting the method of modulation and repetition rate codes according PMCS.

It should be noted that the terms “modulation method” and “order modulation is used in the same meaning. As stated above, “KP” is a package that is encoded in the encoder, and “subpacket” is a code word output from the encoder. The device forming subcode (or the device forming casinoplay turbo code), can be used as the encoder (see Figure 2 in the patent application Korea No. 2001-63518 --Code Generating Apparatus and Method in a Communication System (Method and apparatus for code generation in a communication system, filed by the applicant on 15 October 2001). According to this application the device forming casinoplay turbo code (CDTC), contains a channel encoder for turbo-encoding the input stream of information bits and a generator subcodes for the formation of subcodes by discarding and repeating the code symbols received from the channel encoder. The repetition rate of the codes is equal to R=1/5, has for the channel encoder, and the repetition rate of the codes is R=2/3, 1/3, or 1/6, available for generator subcodes. The first repetition frequency codes is called the fundamental frequency sequence code, and the last repetition frequency codes, the repetition frequency of the subcodes. Subpacket is a term of the criminal code of the rendering code word, encoded with a repetition rate of subcodes. When using a turbo encoder with subpackets is a code word encoded with the basic repetition rate codes. It should be noted that these terms are used in the prior art.

Definition PMCS

It is well known that the increment coefficient encoding increases slowly as the repetition frequency of codes is reduced in a digital communication system that uses codes with error correction. The coefficient coding is a relative factor, resulting from the use of code with error correction, and which otherwise could not be obtained. In other words, the error rate in bits (COB) has gradually reached its point of saturation with decreasing repetition rate codes. On the contrary, with increasing repetition rate codes increment coefficient encoding and COB decrease very rapidly. In the art this phenomenon is well known as the “theory of channel capacity Shannon”. Therefore, the above-mentioned characteristics are not described in detail, and it is necessary to specify that this invention is realized on the basis of known principles.

When the same signal-to-noise ratio (SNR) COB varies within a limited range in accordance with the increase or decrease in order modulation in digital modes the population. In particular, the increased SNR required for digital modulation method with a higher order modulation to provide the same COB. Therefore, if the system uses the specified baud rate modulation symbols, it is possible to provide many combinations of order modulation/frequency of repetition codes.

Given the characteristics of codes with error correction and characteristics of digital modulation is more effective using a modulation method having a low order at low repetition rate codes, such as quadrature phase shift keying (FMC) QPSK, instead of further reducing the repetition rate codes using a modulation method having a high order. On the contrary, would be more appropriate using a modulation method having a high order with a high repetition rate codes to eliminate the increase of error rate.

In this case, since the repetition rate of the codes is calculated to achieve the same efficiency range after determining the order of modulation, so the exact frequency codes cannot be defined to determine the order of the modulation. Therefore, the new function will be defined as the efficiency of the energy spectrum by using a order modulation and repetition frequency codes in accordance with this invention.

IP is odya table transfer rate six data above the main group's proposal L3QS, the number of information symbols of the modulation symbols is a function of the CHICK, and TWI in the transmitter, which can be expressed as

where 1536 (=(1,2288×106)×(1,25×10-3)) is the number pseudotumour (PSH) elements of the signal during a time interval equal to 1.25 msec at a speed of 1,2288 of makeelement/sec. The number of information modulation symbols can be calculated as follows:

After defining the work order modulation repetition rate codes according to Equation (2) as PMCS:

what is a special equation of Equation (2). Equation (3) characterizes PMCS, when the transmission speed of the signal elements is 1,2288 of makeelement/sec and when the duration of the time interval is 1.25 msec. 48 there are a number of modulation symbols, covered with Walsh code of length 32, during a time interval equal to 1.25 msec. Therefore, 48×CHICK gives the number of modulation symbols in a time interval of a duration of 1.25 MS. Therefore, the information modulation symbols will be: 48×CHICK×TWI. When the maximum CHICK (i.e. 32) the number of information modulation symbols will be the product of the duration of transmission for KP (=1.25 msec duration and the interval× TWI) on the transmission speed of the signal elements equal 1,2288 makeelement/sec.

As stated above, PPMCS depends on the size of KP, CHICK, and TWI. If you know these parameters, you can determine PMCS. Therefore, the order of the modulation increases with decreasing repetition rate codes, and Vice versa.

When this order modulation is very low PMCS equivalent to a very low repetition rate code. For example, the order of modulation for the FMC equal to 2. If PMCS=0.5, then the repetition frequency of codes is equal to 1/4 (=0,5/2). On the contrary, very high PMCS equivalent to a very high repetition rate codes. For example, if PMCS=4/3 when the FMC, the repetition frequency of codes equal to 2/3 (=(4/3)/2). Therefore, if there are several modulation techniques, such as FMC, 8-FMN (Phase shift Keying), 16-QAM (quadrature amplitude modulation) and 64-QAM, and if PMCS insignificant, it is preferable to use the FMC with a relatively low order modulation. If PMCS relatively large, then the preferred 8-QPSK, 16-QAM or 64-QAM due to their relatively higher order modulation. Orders modulation in the FMC, 8-QPSK and 16-QAM: 2, 3, and 4, respectively. But if PMCS is neither high nor low, it will not be easy to determine the method of modulation which to choose. Determination of the order of modulation is not based on the true criterion can reduce the throughput of the system is neither. In this invention a method of modulation is chosen as follows.

You must first analyze the range PMCS for each modulation method. Assume that the order of the modulation - k, and repetition rate codes - R. Then, since PMCS=k×R according to Equation (2), R=PPMSC/k. Assuming that Rmaxdefined as the maximum repetition rate code, then

When k=4 (16-QAM) and Rmax=0,8

Determination of the Order Modulation

As noted in connection with Equation (3), PMCS equivalent to the number of information bits transmitted in one symbol. So PPMCS reflects the spectrum efficiency and the same PMCS equivalent of one and the same efficient use of the spectrum. In this case, the order of modulation should be defined as the value that provides the lowest error rate (CRR (in bits) or error rate in the package (COP) in the corresponding operating range SNR, taking into account the trade-off between modulation and coding. If the method of modulation with minimum COP can be determined by PMCS, then you can define the order of the modulation. In this invention it PMCS calculated, and the method of modulation is determined according to PMCS.

To determine the most effective method module the AI for each of the six dimensions KP in the basic proposal of the group L3QS modelling was conducted in accordance with the terms and conditions specified in Table 1.

Referring to Table 1, the simulation was performed on a physical channel additive white Gaussian noise (abgs). As indicated above, channel transmitter may consist of turbolader, generator subcodes and some set of modulators having different orders of modulation. The modulators are, for example, the modulator of the FMC order modulation 2, the modulator 8-FMN order modulation 3, and the modulator 16-QAM order modulation 4. The basic repetition frequency codes is 1/5, and channel transmitter contains interleaver partially reverse the order of the bits (COPB). The decoder for channel receiver, the corresponding channel to the transmitter, performs decoding using maximum a posteriori algorithm (map, MaxLogMAP). Replays make up to eight times.

The simulation results are presented in figures 1, 2 and 3. Refer to Figure 1, if the size of the CP=384 bits, Ec/Nt(dB)required to provide 1% CPC at FMC, 8-QPSK and 16-QAM, illustrated relatively PMCS. Ec/Nt(dB) is a variation of the SNR and indicates the ratio of the energy of a single element signal and power density of the noise. Therefore, with increasing Ec/Nt(dB) requires more power to get the same COP.

According to Figure 1 the required Ec/Nt(dB) increases with PMCS, and changes in Ec/Nt(dB) relative to the change is reported in PMCS are different in accordance with the methods of modulation. If PMCS is 1.5, then the line for the FMC is over the line for 16-QAM. If PMCS less than or equal to 1.5, then the FMC has the best characteristics. From the point of view of performance 8-FMN is midway between the FMC and 16-QAM. When PMCS equals 1.5, the repetition rate codes FMC, 8-QPSK and 16-QAM is equal to 3/4, 1/2 and 3/8, respectively. Modulation methods have the same characteristics when PMCS equal to 1.5, this means that the same characteristics are provided regardless of modulation techniques, when one modulation symbol passes the 1.5-bit information. When changing the CHICK, and TWI values change only on the ordinate and the angle of the lines remains unchanged.

Figure 2 illustrates three lines of modulation techniques, pointing Ec/Nt(dB), you need to provide 1% CPC in relation to PMCS, when the size of the CP=1536 bits. These lines show the same characteristics as the line in the case when the size of the CP=384 bits (illustrated in figure 1). Lines intersect at the threshold value PMCS, equal to 1.5; and the FMC and 16-QAM have the best characteristics above and below the threshold, respectively. Similarly, the lines in figure 1 characteristics of the modulation techniques change when PMCS, equal to 1.5, when the size of the CP=1536 bits.

Figure 3 illustrates three lines of modulation techniques, the desired Ec/Nt(dB) to provide 1% CPC referred by the Yu to PMCS, when the size of the CP=3072 bits. Similarly, when the size of the CP=384 bits and 1536 bits, conversion happens characteristics of the FMC and 16-QAM when PMCS=1,5.

From this simulation we can conclude that regardless of the size of the CP CPM and 16-QAM effective if the value is below PMCS=1.5, when PMCS=1.5 or above, respectively.

Regardless of the size of the CP there is a unique threshold value PMCS, which determine the order of the modulation. But the result of the simulation does not take into account that this method of amplitude modulation (AM), as 16-QAM, gives the worst performance, than this method is QPSK-modulation 16-QAM as the FMC and 8-FMN in the real hardware environment. If, taking into account differences in the performance of AM and FMN, there are theory or simulation results, the threshold value PPMCS may vary from 1.5; and there may be some set of thresholds PMCS. Therefore, the existing modulation methods are not limited only to the FMC and 16-QAM, but can also be used with other modulation methods.

Below is a description of a variant of implementation of the present invention in the determination of the order modulation according to the principle, obtained by simulation results.

An implementation option

The process of selecting a modulation method according to a variant implementation of the invention below is Slagelse in the case of the presence of the transmitter, with two modulators, i.e., the modulator 16-QAM and the CPM modulator. But the number of modulators is not limited. The following description assumes that the speed of the signal elements is 1,22878 of makeelement/sec, the duration of the time interval is 1.25 sec, and the length of the Walsh code is 32.

Figure 4 is a block diagram illustrating the process of selecting a modulation method (or order modulation) in accordance with the embodiment of the present invention. Further, the device for determining the modulation method is referred to as the modulation selector.

Refer to Figure 4, the modulation selector performs initialization in step 411. If the selector switch of the modulator determines the size of the CP determines CHICK, and TWI. The modulator selector calculates PMCS using the parameters of equation (3) in step 413. At step 415, the modulator selector compares PMCS threshold PMCS (PMCS threshold, MPR_THR). For example, the threshold value PMCS preferably set at a value of 1.5. If PMCS exceeds this threshold value, the modulator selector selects 16-QAM and the modulator 16-QAM at step 417. On the other hand, if PMCS less than or equal to the threshold value, the modulator selector selects the CPM and the CPM modulator at step 419.

Figure 5 is a block diagram of the device of choice modulator that performs the algorithm, illustrated in the figure 4, according to a variant implementation of the invention. Refer to Figure 5, the selector 501 modulator outputs a select signal indicating the optimum modulator, fulfilling stages 411-419, shown on Figure 4. That is, the selector 501 modulator calculates PMCS using size KP, using CHICK and TWI and compares PMCS with a threshold value. If PMCS exceeds this threshold value, the selector 501 modulator outputs the first switching signal (SW=B). If PMCS less than or equal to the threshold value, it outputs the second switching signal (SW=A). The switch 503 is switched in accordance with the switching signal received from the selector 501 modulation, and outputs the input data in the form of subpacket from the encoder, the modulator 505 CFM or modulator 507 16-QAM. The modulator 505 FMC FMC provides modulation data, and 16-QAM-modulator 507 performs 16-QAM modulation data.

To select one of the modulators with different orders for modulation of subpacket, which is the codeword output from the encoder, the selector 501 modulator receives PMCS by calculating the ratio of the size of gearbox and number information modulation symbols, and compares PMCS threshold value (MPR_THR). The number of information modulation symbols determined by the duration of transmission, gearbox, CHICK, and a given transmission speed of the signal elements. P. and CHICK maximum number of information modulation symbols is the product of the duration of transmission on the transmission speed of the signal elements. If PMCS exceeds the threshold value, then choose modulator with higher order modulation (e.g., 16-QAM). If PMCS less than or equal to the threshold value, then choose modulator with a lower order modulation (e.g., modulator FMC).

Although the selector 501 modulator selects or CPM, or 16-QAM by comparing PMCS threshold value, specialists in the art will understand that the selector 501 modulator can be configured so that it will choose one of the FMC, 8-QPSK and 16-QAM. For example, the first threshold value (PMCS threshold, R_R) set to select the FMC or 8-FMN, and the second threshold value (PMCS thresholdΔ, MPR_THRΔ) set to select 8-QPSK or 16-QAM.

Because PMCS is a work order modulation and repetition frequency codes, therefore, in the embodiment of the present invention can also determine the frequency of repetition codes. That is, after calculating PMCS and determine the order modulation to select one of the modulators can be output frequency codes for the encoder.

6 illustrates the device of choice demodulator corresponding to the device selection of the modulator illustrated in figure 5. Refer to Fig.6, the selector 601 demodulator determines to be used in the transmitter modulation technique by comparing P IS MCSC, calculated size of the gearbox, using CHICK and TWI, received from the receiver, with the threshold value. Moreover, the selector 601 demodulator determines the size of the CP determines CHICK, and TWI, used in the transmitter at step 611, and calculates PMCS parameters using equation (3) in step 613. Then, the selector 601 demodulator compares PMCS threshold value used in the transmitter, at step 615. If PMCS exceeds this threshold value, the selector 601 demodulator outputs the first switching signal (SW=) that specifies the 16-QAM demodulator 607, at step 617; and otherwise, it outputs the second switching signal (SW=A), indicating the FMC-demodulator 605, at step 619. Switch 603 switches the input data, which is adopted from transmitter data in the FMC-demodulator 605 or 16-QAM-demodulator 607 according to the switching signal. QPSK-demodulator 605 performs the FMC-demodulates the data received from the switch 603. 16-QAM-demodulator 607 performs 16-QAM-demodulation of data received from the switch 603.

In the above description, the threshold value in the embodiment of the present invention is an empirical value, for example to 1.5. No currently available tables data rate transmitter and the receiver can determine the modulation method using the size of the CP, with OSU CHICK, and TWI.

In accordance with the description of the present invention, the optimum modulation method can be defined according to a given hardware environment. Therefore, the efficiency of the transmission system is brought to the maximum.

Although the invention is illustrated and described with reference to specific preferred implementation, this implementation is only an example. That is, in the above embodiment describes the FMC, 8-QPSK and 16-QAM, but this invention is applicable also to other methods of modulation. Specialists in the art it will be clear that the invention can perform various changes in form and detail without departure from the essence and scope of the invention defined in the attached claims.

1. The selection method of one of the modulators having different orders of modulation for modulating subpacket, which is the codeword output from the encoder that accepts moderny package (CP), namely, that calculates the product of the order modulation frequency codes (PMCS), which is the ratio of the size of gearbox and number information modulation symbols, compare PMCS with some threshold value to select one of the modulators and choose modulator having a relatively high order modulation, the number of modulators, if MRP is the IC exceeds the threshold value, and modulator having a relatively low order modulation, the number of modulators, if PMCS less than or equal to the threshold value.

2. The method according to claim 1, characterized in that the number of information modulation symbols is determined by the duration of transmission, gearbox and speed data.

3. The method according to claim 1, characterized in that the number of information modulation symbols is multiplied by the number of available Walsh codes, the number of time intervals based on one subpacket and the number of signal elements for a given Walsh code length.

4. The method according to claim 3, characterized in that the number of signal elements for a given Walsh code length is 48.

5. The method according to claim 2, characterized in that if you set the maximum length of the Walsh code, the information modulation symbols is the product of the duration of transmission gearbox speed data transfer.

6. The method according to claim 1, characterized in that the threshold value is set to select either of the modulator quadrature phase-shift keying (CPM modulator), or modulator hexadecimal quadrature amplitude modulation (16-QAM modulator).

7. The method according to claim 6, characterized in that it further selects 16-QAM-modulator, if PMCS exceeds the threshold value.

8. The method according to claim 6, characterized in that it additionally choose the FMC-modulate is, if PMCS less than or equal to the threshold value.

9. The transmitter in the communication system containing an encoder for encoding modernage package (CP), a set of modulators having different orders of modulation for modulating subpackets, which code words output from the encoder, a selector for selecting one of the modulators by comparing the works order modulation frequency codes (PMCS), which is the ratio of the size of gearbox and number information modulation symbols with a certain threshold value, and the modulator has a relatively high order modulation, if PMCS exceeds the threshold value, and has a relatively low order modulation, if PMCS less than or equal to the threshold value, and a switch for switching the output of the encoder on the selected modulator according to the comparison result selector.

10. The transmitter according to claim 9, characterized in that the number of information modulation symbols is multiplied by the number of available Walsh codes, the number of time intervals based on one subpacket and the number of signal elements for a given Walsh code length.

11. The transmitter of claim 10, wherein the number of signal elements for a given Walsh code length is 48.

12. The transmitter according to claim 9, wherein the selector determines the number of information modulating the traditional characters for the duration of the transmission gearbox and the specified data transfer rate.

13. The transmitter section 12, characterized in that if you set the maximum length of the Walsh code, the selector determines the number of information modulation symbols by calculating the product of the duration of the transmission gearbox speed data transfer.

14. The transmitter according to claim 9, characterized in that the combination of the modulator includes a modulator quadrature phase-shift keying (CPM modulator and modulator hexadecimal quadrature amplitude modulation (16-QAM-modulator).

15. The transmitter 14, wherein the selector selects the 16-QAM modulator, if PMCS exceeds the threshold value.

16. The transmitter 14, wherein the selector selects the CPM modulator, if PMCS less than or equal to the threshold value.

17. The method for determining the order of modulation and repetition rate codes in a communication system having an encoder for encoding modernage package (KP) and some set of modulators for modulating subpacket, which is the codeword output from the encoder, namely, that calculates the product of the order modulation frequency codes (PMCS), which is the ratio of the size of gearbox and number information modulation symbols, and compare PMCS with some threshold value, and determine the order modulation to select one of the modulators with consider is eno high order modulation, if PMCS exceeds the threshold value, and have a relatively low order modulation, if PMCS less than or equal to the threshold value, and determines the repetition rate codes for the encoder according PMCS and order modulation.

18. The method according to 17, characterized in that the number of information modulation symbols is multiplied by the number of available Walsh codes, the number of time intervals based on one subpacket and the number of signal elements for a given Walsh code length.

19. The method according to p, characterized in that the number of signal elements for a given Walsh code length is 48.

20. The method according to 17, wherein the threshold value is set to select either of the modulator quadrature phase-shift keying (CPM modulator), or modulator hexadecimal quadrature amplitude modulation (16-QAM modulator).

21. The method according to claim 20, characterized in that it further selects 16-QAM-modulator, if PMCS exceeds the threshold value.

22. The method according to claim 20, characterized in that it additionally choose the CPM modulator, if PMCS less than or equal to the threshold value.

23. The transmitter in the communication system containing an encoder for encoding modernage package (CP), a set of modulators having different orders of modulation for modulating subpackets, which code words output from the and of the encoder, a selector to calculate work order modulation frequency codes (PMCS), which is the ratio of the size of gearbox and number information modulation symbols, for comparison PMCS with some threshold value, to determine the order modulation to select one of the modulators having a relatively high order modulation, if PMCS exceeds the threshold value, and have a relatively low order modulation, if PMCS less than or equal to the threshold value, and for determining the repetition frequency codes for the encoder according PMCS and order modulation and a switch for switching the output of the encoder on the selected modulator according to the comparison result selector.

24. The transmitter according to item 23, wherein the selector determines the number of information modulation symbols by multiplying the number of available Walsh codes, the number of time intervals based on one subpacket and the number of signal elements for a given Walsh code length.

25. The transmitter according to paragraph 24, wherein the number of signal elements for a given Walsh code length is 48.

26. The transmitter according to item 23, wherein the combination of the modulator includes a modulator quadrature phase-shift keying (CPM modulator and modulator hexadecimal quadrature amplitude modulation (16-QAM-modulator).

27 the Transmitter p, wherein the selector selects the 16-QAM modulator, if PMCS exceeds the threshold value.

28. The transmitter p, wherein the selector selects the CPM modulator, if PMCS less than or equal to the threshold value.



 

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FIELD: communication systems using variable transfer process; optimizing modulation process and code repetition frequency in given hardware environment.

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4 cl, 1 tbl, 9 dwg

FIELD: radio engineering; demodulation of sixteen-position quadrature amplitude keyed signals.

SUBSTANCE: newly introduced in prior-art sixteen-position quadrature amplitude keyed (KAM-16) signal demodulator are fifth and sixths counters and phase error correction unit; there units make it possible to execute following new operations with signal: counting of signal points within count interval, their quantity enabling evaluation of phase error due to unwanted lock-on; correction of calculated phase error in phase error correction unit.

EFFECT: enlarged functional capabilities.

2 cl, 5 dwg, 1 tbl

FIELD: information technology.

SUBSTANCE: present invention relates to methods of detecting hierarchically encoded data. In one detection scheme, log-likelihood ratio (LLR) is derived for code bits of the first data stream, based on received data symbols. Interference caused by the first data stream is evaluated. LLR is derived for code bits of the second data stream, based on the LLR for code bits of the first data stream and evaluated interference. LLR for code bits of the first data stream is decoded to obtain decoded data from the first data stream. Decoded data are recoded and re-modulated to obtain re-modulated symbols. Interference caused by the first data stream is evaluated based on the re-modulated symbols. LLR for the first data stream can be derived from received symbols in real time without buffering the received symbols. LLR for the second data stream can be derived after decoding the first data stream.

EFFECT: more efficient detection of hierarchically encoded data.

34 cl, 6 dwg

FIELD: physics.

SUBSTANCE: method of relaxed solution for demodulating a received signal α+iβ with quadrature amplitude modulation (QAM) involves deriving several values of a conditional probability vector, where each is a relaxed solution value which corresponds to the position of a stiff solution bit, using a function which includes an operation for conditional definition from the quadrature phase component and inphase component of the received signal. The method of solving for the conditional probability vector for demodulation of the first half of the complete number of bits is identical to the solution method for demodulating the remaining half of bits, and is determined by replacing the value of the quadrature phase component and the value of the inphase component with each other.

EFFECT: more accurate processing a received signal.

29 cl, 15 dwg

FIELD: information technologies.

SUBSTANCE: method is realised using the following facilities, where a DVB-T modulator comprises serially joined units, an interface, a randomiser, a Reed-Solomon encoder, a convolution interleaver, a convolution coder, a bit interleaver, a symbol interleaver, a QAM shaper, a calculator of reverse quick Fourier transform (RQFT calculator), a digital to analogue converter (DAC), a high-frequency unit (HF unit) and a shaper of pilot signals at the inlet of the QAM shaper, and also the following units are additionally introduced: a unit of packets breakdown, receiving information from the interface and sending it to the randomiser and a control unit, a register receiving signals from the randomiser and sending a signal to the Reed-Solomon coder and the convolution interleaver, the control unit receiving information from the unit of packets breakdown, and outlets are connected to all modulator units.

EFFECT: reduced requirements to a computing device due to optimisation of processes of synchronising operation of all units in whole, using less efficient computing devices.

1 dwg

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