JP4574484B2 - Reception device, received signal processing method, and communication system - Google Patents

Description

  The present invention relates to a receiving apparatus, a received signal processing method, and a communication system.

As is well known, the Frequency Division Multiplex (FDM) system divides a predetermined frequency band and assigns it to a plurality of lines, and transmits / receives signals on each line (hereinafter referred to as individual line signals) as frequency multiplexed signals. It is a method to do. FIG. 7 shows the configuration of a frequency multiplexed signal when a predetermined frequency band is equally divided and assigned to a plurality of individual line signals among such frequency division multiplexing systems. As shown in this figure, each of the frequency multiplexed signals F has the same bandwidth f _wc and the center frequencies fc1, fc2, fc3,..., Fcn are predetermined frequency intervals f _int (f _int ≧ f _wc ). Are composed of a plurality (n) of individual line signals k1 to kn arranged continuously. In FIG. 7, f _wsys is a frequency bandwidth occupied by the wireless communication system, and f _α is an arbitrary frequency for realizing the wireless communication.

  FIG. 8 is a block diagram showing a first configuration example of the frequency multiplexing signal F receiving apparatus. This receiving apparatus performs frequency conversion for each baseband signal t1 to tn by supplying the frequency multiplexed signal F captured by the antenna A in parallel to mixers B1 to Bn provided for the individual line signals k1 to kn. By supplying the baseband signals t1 to tn to bandpass filters D1 to Dn provided in the subsequent stages of the mixers B1 to Bn, baseband signals u1 to un corresponding to the individual line signals k1 to kn (individually) Baseband signals) are selectively discriminated, and the individual baseband signals u1 to un are supplied to the A / D converters E1 to En provided at the subsequent stages of the bandpass filters D1 to Dn, respectively. The individual received data d1 to dn (digital signals) corresponding to the band signals u1 to un (analog signals) are converted into digital signals, and the individual received data d1 to dn are converted into digital signals by the digital signal processing unit G It is what you want to process. The local signal generators C1 to Cn are provided for the respective mixers B1 to Bn, and the frequency is the center of each individual line signal so as to frequency-convert the individual line signals k1 to kn into baseband signals t1 to tn. Local signals set in the same manner as the frequency numbers fc1, fc2, fc3,..., Fcn are output to the mixers B1 to Bn, respectively. For example, Japanese translations of PCT publication No. 2000-506689 discloses a receiving apparatus in which a plurality of components such as mixers are used as many as the number of individual line signals included in the frequency multiplexed signal F as described above.

FIG. 9 is a block diagram showing a second configuration example of the receiving apparatus for the frequency multiplexed signal F. This receiver receives the frequency multiplexed signal F captured by the antenna A and outputs it to the mixer B. The mixer B mixes the frequency multiplexed signal F and the local signal s input from the local signal generator C. Frequency conversion is performed, and the baseband signal t is output to the low-pass filter D. The local signal generator C outputs a local signal s set to a frequency for frequency conversion of the frequency multiplexed signal F to the baseband frequency band to the mixer B. The low pass filter D removes the high frequency component of the baseband signal t and outputs it to the A / D converter E. The A / D converter E converts the filtered baseband signal t (analog signal) into a digital signal d. Output to the digital signal processing unit G. The digital signal processing unit G uses the digital bandpass filters D′ 1 to D′ n to correspond the digital signal d to the individual line signals k1 to kn included in the frequency multiplexed signal F. After discrimination into the individual reception data d1 to dn, signal processing of the individual reception data d1 to dn is performed.
Special Table 2000-506669

 By the way, in the first configuration example, the mixers B1 to Bn, the local signal generators C1 to Cn, the band pass filters D1 to Dn, and the A / D converter according to the number of individual line signals included in the frequency multiplexed signal F. A large number of analog high-frequency components such as E1 to En are required, which complicates the circuit configuration and increases the device cost.

 On the other hand, in the second configuration example, the number of parts can be reduced as compared with the first configuration example. However, the sampling frequency of the A / D converter E is frequency-converted to at least the baseband frequency band (or IF frequency band). It is necessary to set it to twice the maximum frequency of the frequency multiplexed signal F (in the first configuration example, it may be set to twice the maximum frequency for each separated individual baseband signal). Therefore, an extremely high-speed A / D converter E is required, and a digital signal processing unit G in the subsequent stage must also be used with a high operating speed, so that relatively expensive parts are required. There arises a problem that the apparatus cost increases.

 The present invention has been made in view of the above-described circumstances, and an object thereof is to reduce the apparatus cost of a receiving apparatus that receives a frequency-multiplexed signal.

In order to achieve the above object, the present invention employs the following means.

A receiving apparatus according to the present invention is an apparatus for receiving a frequency multiplexed signal in which an individual line signal having a predetermined bandwidth is continuously or discontinuously arranged at a certain frequency interval equal to or greater than the bandwidth. A receiving means for receiving a signal, and P in parallel corresponding to P groups obtained by extracting the individual line signal from the frequency multiplexed signal every (P-1) (P is an integer of 2 or more). A predetermined individual line signal within each group having a center frequency that is a low frequency signal having a center frequency that is a natural number multiple of the frequency interval, or a center frequency that is greater than the center frequency and satisfies the sampling theorem. Frequency conversion means for frequency-converting the frequency multiplexed signal so as to become a low frequency signal, and an individual low frequency signal corresponding to an individual line signal from the low frequency signal as an individual reception signal Filtering means for selectively discriminating; a plurality of A / D conversion means for sampling each of the individual low-frequency signals at a P-times oversampling frequency corresponding to P times the frequency interval; and each of the A / D conversion means Signal processing means for performing a predetermined reception process on the output signal.

  In the present invention, the frequency conversion means may convert the frequency-multiplexed signal into a low-frequency signal so that an individual line signal having the lowest frequency among the groups becomes an intermediate frequency signal satisfying a baseband signal or a sampling theorem. The frequency conversion is performed.

Received signal processing method according to the present invention, receives for performing signal processing receives the frequency multiplexed signal continuously or discontinuously arranged on an individual line signal is a constant frequency interval of at least the bandwidth having a predetermined bandwidth A signal processing method comprising: a first step of receiving the frequency-multiplexed signal; and extracting the individual line signal from the frequency-multiplexed signal every (P−1) (P is an integer of 2 or more). P in parallel corresponding to each group, and a predetermined individual line signal in each group is a low frequency signal having a center frequency that is a natural number multiple of the frequency interval, or larger than the center frequency and A second step of frequency-converting the frequency-multiplexed signal so as to obtain a low-frequency signal having a center frequency satisfying the sampling theorem, and corresponding to the individual line signal from the low-frequency signal. A third step of selectively discriminating individual low frequency signals as individual received signals, and A / D conversion by sampling each of the individual low frequency signals at a P-times oversampling frequency corresponding to P times the frequency interval. A fourth step, and a fifth step of performing a predetermined reception process on the digital signals after each A / D conversion.

  In the second step of the present invention, in the second step, the frequency-multiplexed signal is converted into a low-frequency signal so that the individual line signal having the lowest frequency in each group becomes an intermediate frequency signal satisfying the baseband signal or the sampling theorem. The frequency conversion is performed.

Communication system according to the present invention includes a transmission device for transmitting a frequency multiplexed signal continuously or discontinuously arranged on an individual line signal is a constant frequency interval of at least the bandwidth having a predetermined bandwidth, to the present invention The receiving apparatus.

According to the present invention, the individual line signals k1 to kn included in the received frequency multiplexed signal F are arranged continuously or discontinuously at a constant frequency interval f _int , and the bandwidth f _wc of each individual line signal k1 to kn. if (f _int ≧ f _wc) are the same, by setting the sampling frequency f _s equal to the frequency interval f _int, it is possible to set the a / D converter to all the same sampling frequency f _s . Furthermore, since this sampling frequency f _s is comparable to the frequency of the baseband signal or intermediate frequency signal, it is not necessary to increase the speed of the A / D converter. Further, if the sampling frequency f _s of the A / D converter is low, the operation speed of the signal processing means at the subsequent stage can be kept low. Therefore, it is possible to reduce the component costs of the A / D converter and the signal processing means. On the other hand, in this receiving apparatus, only one frequency converting means is provided in the preceding stage of the filter (filtering means), the number of parts can be reduced as compared with the prior art, and the apparatus cost can be reduced.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing a functional configuration of a receiving apparatus according to the first embodiment of the present invention. As shown in this figure, this receiving apparatus includes an antenna (receiving means) A, a mixer B, a local signal generator C, band pass filters (filtering means) D1 to Dn, and an A / D converter (A / D converting means). E1 to En and a digital signal processing unit (signal processing means) G. The mixer B and the local signal generator C constitute frequency conversion means. The receiving apparatus performs reception and signal processing of the frequency multiplexed signal F shown in FIG.

In FIG. 1, the antenna A captures the frequency multiplexed signal F and outputs it to the mixer B. Local signal generator C outputs a local signal s having a center frequency f _c1 and the local frequency set to the same individual line signal k1 of frequency division multiplexed signal F to the mixer B. The mixer B performs frequency conversion by mixing (multiplying) the frequency multiplex signal F captured by the antenna A and the local signal s input from the local signal generator C, and performs frequency conversion after the frequency conversion ( Baseband signal) t is output to bandpass filters D1 to Dn.

  The band-pass filter D1 has a passband frequency set so as to pass only the baseband signal (individual baseband signal) u1 corresponding to the individual line signal k1 of the baseband signal t. The individual baseband signal u1 Is output to the A / D converter E1. Similarly, the passband frequencies of the bandpass filters D2 to Dn are set so that only the individual baseband signals u2 to un corresponding to the individual line signals k2 to kn pass, and the signal individual baseband signal u2 -Un are output to the A / D converters E2-En, respectively.

A / D converter E1 is the sampling frequency f _s which is set equal to the frequency interval f _int the frequency division multiplexed signal F, by sampling the individual baseband signals u1, individual reception data individual baseband signals u1 is an analog signal It converts into d1 and outputs it to the digital signal processor G. A / D converter E2~En likewise, at the sampling frequency _{f s} which is set equal to the frequency interval f _int, and converts each sample the individual baseband signals u2~un the individual reception data d2~dn digital The signal is output to the signal processing unit G. The digital signal processing unit G performs predetermined digital signal processing on the individual received data d1 to dn.

  Next, the operation of the receiving apparatus according to the first embodiment configured as described above will be described.

First, the frequency multiplexed signal F is captured by the antenna A, then mixed with the local signal s having the local frequency _fc1 by the mixer B, and frequency-converted to the baseband signal t. Here, in the baseband signal t, if the center frequencies of the individual line signals k1 to kn after frequency conversion are fb1, fb2, fb3,..., Fbn, the bandpass filters D1 to Dn discriminate from the baseband signal t. The individual baseband signals u1 to un corresponding to the individual line signals k1 to kn thus obtained have frequency characteristics as shown in FIG.

  FIG. 2A shows the frequency characteristics of the individual baseband signal u1 corresponding to the individual line signal k1. FIG. 2B shows frequency characteristics of the individual baseband signal u2 corresponding to the individual line signal k2. FIG. 2C shows frequency characteristics of the individual baseband signal u3 corresponding to the individual line signal k3. FIG. 2D shows the frequency characteristics of the individual baseband signal un corresponding to the individual line signal kn.

As shown in FIG. 2 (a), the center frequency fb1 is 0Hz next individual baseband signals u1 Further, since the frequency interval f _int ≧ bandwidth f _wc, the maximum frequency of the individual baseband signals u1 (center frequency fb1 + The bandwidth f _wc / 2) is equal to or less than the frequency interval f _int / 2. Accordingly, by setting the sampling frequency f _s of the A / D converter E1 to be the same as the frequency interval f _int , a sampling frequency f _s that is twice or more the maximum frequency of the individual baseband signal u 1 is set, and the result Satisfy the sampling theorem. That is, the sampling frequency f _s of the A / D converter E1, it is possible set to the value of the baseband frequency band.

On the other hand, as shown in FIG. 2 (b), the center frequency fb2 individual baseband signals u2, the frequency interval f _int, i.e. the same as the sampling frequency f _s. In this case, the sampling theorem, if a natural number multiple of the center frequency fb2 is the sampling frequency f _s, similarly to FIG. 2 (a), the center frequency fb2 individual baseband signal u2 are convolved to 0 Hz, after all, The maximum frequency of the individual baseband signal u2 can be handled as a frequency interval f _int / 2 or less. In other words, the maximum frequency of the individual baseband signals u2 would otherwise, since the center frequency fb2 + bandwidth f _{wc / 2,} it is necessary to set more than double this maximum frequency as the sampling frequency f _s, of the if the center is a natural number multiple of the frequency fb2 is the sampling frequency f _s as the maximum frequency of the individual baseband signals u2 can be treated as less frequency interval f _int / 2, the sampling frequency of the a / D converter E2 f It is possible to set _s to be the same as the sampling frequency f _s of the A / D converter E1.

Similarly, as shown in FIG. 2 (c), the center frequency fb3 individual baseband signals u3 is, 2 · f _int, i.e. becomes the same as twice the sampling frequency f _s, also in this case, the center frequency fb3 Is a natural number multiple of the sampling frequency f _s , the center frequency fb3 of the individual baseband signal u3 is convoluted to 0 Hz, and as a result, the maximum frequency of the individual baseband signal u3 is treated as a frequency interval f _int / 2 or less. be able to. That is, it is possible to set the sampling frequency _{f s} of the A / D converter E3 equal to the sampling frequency _{f s} of the A / D converters E1 and E2. Then, as shown in FIG. 2 (d), the center frequency fbn individual baseband signals un is, (n-1) · f int, i.e. the sampling frequency _{f s} (n-1) times and is the same, Again, since the center frequency fbn is a natural number multiple of the sampling frequency f _s, the center frequency fbn individual baseband signal un is convolved to 0 Hz, eventually, the maximum frequency of the individual baseband signals un the frequency interval f _int / 2 can be treated as follows, the sampling frequency _{f s} of the a / D converter E1 to En, all can be set to the same sampling frequency _{f s.}

As described above, according to the first embodiment, the frequency multiplexed signal F to be received is configured as shown in FIG. 7, that is, the individual line signals k1 to kn have a constant frequency interval f _int (specifically, the frequency interval f _int are continuously arranged in a natural number multiple) of, and if each individual line signal bandwidth f _wc of k1~kn is below the frequency interval f _int, frequency discrete line signal k1 of the lowest frequency to a baseband signal using a local signal s to convert, by setting the sampling frequency f _s equal to the frequency interval f _int, it is possible to set all the a / D converter E1~En the same sampling frequency f _s. Furthermore, since the sampling frequency f _s is set to be twice or more the maximum frequency of the individual baseband signal u1 having the lowest frequency, the high-speed A / D converters E1 to En are not necessary. Also, this way A / D converter E1~En sampling frequency f _s is lower, it is possible to suppress the operation speed of the subsequent digital signal processing unit G is also low. Therefore, it is possible to reduce the component costs of the A / D converters E1 to En and the digital signal processing unit G. On the other hand, as can be seen from a comparison between FIG. 1 and FIG. 8, in this receiving apparatus, the mixer B and the local signal generator C provided in the previous stage of the bandpass filters D1 to Dn may be a pair. It is possible to further reduce the number of parts and contribute to reducing the part cost.

  Conventionally, since the number of quantization bits of the A / D converter must correspond to all the power that each individual baseband signal can take, for example, the communication method of one individual baseband signal is BPSK (Binary Phase Shift Keying). Even if it is a method that does not require a relatively large amplitude, such as), a very wide dynamic range (for example, 100 dB or more at 16 bits) is required, resulting in an increase in power consumption. However, according to this receiving apparatus, the number of quantization bits of each of the A / D converters E1 to En only needs to correspond to the power that can be taken by the individual baseband signal k1, so that the dynamic range can be reduced and consumed. Electric power can be reduced.

By the way, in today's frequency crosstalk situation, in order not to cause radio interference to other existing systems or to avoid interference from existing systems, a specific frequency (in FIG. 3, individual line signal k2 is used). ) May not be necessary. Even if the individual line signals are discontinuous as described above, if the faulty individual line signal k2 is thinned out while maintaining an arrangement that is an integral multiple of the frequency interval f _int as shown in FIG. 4 is possible. As shown in this figure, the band-pass filter D2 and the A / D converter E2 can be removed by thinning out the individual line signal k2, and the number of parts can be further reduced.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
FIG. 5 is a block diagram showing a functional configuration of a receiving apparatus according to the second embodiment of the present invention. As shown in this figure, the receiving apparatus includes an antenna A, a first mixer B1, a second mixer B2, a first local signal generator C1, a second local signal generator C2, bandpass filters D1 to D4, A / It consists of D converters E1 to E4 and a digital signal processing unit G. Note that this receiving apparatus performs double oversampling in the A / D converters E1 to E4. In FIG. 5, the same components as those in FIG.

The antenna A captures the frequency multiplexed signal F and outputs it to the first mixer B1 and the second mixer B2. First local signal generator C1 outputs a local signal s1 having a center frequency f _c1 and the local frequency set to the same individual line signal k1 of frequency division multiplexed signal F to the first mixer B1. Second local signal generator C2 outputs a local signal s2 having a local frequency is set to be the same as the center frequency f _c2 of the individual line signal k2 of frequency division multiplexed signal F to the second mixer B2. The first mixer B1 mixes (multiplies) the frequency multiplexed signal F captured by the antenna A and the local signal s1 input from the first local signal generator C1 to perform frequency conversion, and generates a baseband signal t1. Output to bandpass filters D1 and D3. Although not shown, the band-pass filters are provided by the number (n) of individual line signals included in the frequency multiplexed signal F, and the baseband signal t1 is an odd-numbered band-pass filter D5, D7. It is entered in…. The second mixer B2 performs frequency conversion by mixing (multiplying) the frequency multiplexed signal F captured by the antenna A and the local signal s2 input from the second local signal generator C2, and generates a baseband signal t2. Output to bandpass filters D2 and D4. Although not shown, the baseband signal t2 is input to even-numbered bandpass filters D6, D8,.

  The bandpass filters D1 to D4 have their passband frequencies set so as to pass only the individual baseband signals u1 to u4 corresponding to the individual line signals k1 to k4, and the individual baseband signals u1 to u4. Are output to the A / D converters E1 to E4, respectively. Although not shown, n A / D converters are also provided, and the individual baseband signals u5 to un are input to the A / D converters E5 to En, respectively.

The A / D converters E1 to En sample the individual baseband signals u1 to un at the sampling frequency f _s (= 2f _int ) set to twice the frequency interval f _int to obtain the individual received data d1 to dn, respectively. Convert and output to the digital signal processing unit G. The digital signal processing unit G performs predetermined digital signal processing on the individual received data d1 to dn.

  Next, the operation of the receiving apparatus according to the second embodiment configured as described above will be described.

First, the frequency multiplexed signal F is captured by the antenna A, then mixed with the local signal s1 having the local frequency _fc1 by the first mixer B1, and is frequency-converted to the baseband signal t1. Here, in the baseband signal t1, assuming that the center frequencies of the individual line signals k1 to kn after frequency conversion are fb1, fb2, fb3,. The individual baseband signals u1, u3, u5... corresponding to the individual line signals k1, k3, k5... discriminated from t1 have frequency characteristics as shown in FIG. On the other hand, the frequency multiplexed signal F is mixed with the local signal s2 having the local frequency _fc2 by the second mixer B2, and is frequency-converted to the baseband signal t2. Here, in the baseband signal t2, assuming that the center frequencies of the individual line signals k1 to kn after frequency conversion are fb1 ′, fb2 ′, fb3 ′,..., Fbn ′, the bandpass filters D2, D4, D6. The individual baseband signals u2, u4, u6... Corresponding to the individual line signals k2, k4, k6... Discriminated from the baseband signal t2 by the above have frequency characteristics as shown in FIG.

As shown in FIG. 6A, the center frequency fb1 of the individual baseband signal u1 is 0 Hz, and the maximum frequency of the individual baseband signal u1 is equal to or less than the frequency interval f _int / 2. Therefore, by setting the sampling frequency f _s of the A / D converter E1 to twice the frequency interval f _int , a sampling frequency f _s that is four times or more the maximum frequency of the individual baseband signal u1 is set. As a result, double oversampling is performed. As for the A / D converters E3, E5,..., As described in the first embodiment, the same sampling frequency f _s as that of the A / D converter E1 can be set, and double oversampling is performed. Is possible.

On the other hand, as shown in FIG. 6B, the center frequency fb2 ′ of the individual baseband signal u2 is 0 Hz, and the maximum frequency of the individual baseband signal u2 is equal to or less than the frequency interval f _int / 2. Therefore, by setting the sampling frequency f _s of the A / D converter E2 to twice the frequency interval f _int , a sampling frequency f _s that is four times or more the maximum frequency of the individual baseband signal u2 is set. As a result, double oversampling is performed. As for the A / D converters E4, E6,..., As described in the first embodiment, the same sampling frequency f _s as that of the A / D converter E2 can be set, and double oversampling is performed. Is possible.

As described above, according to the second embodiment, the frequency-multiplexed signal F is frequency-converted in two systems, the odd-numbered individual baseband signal is discriminated in one system, and the even-numbered individual in the other system. By discriminating the baseband signal, an individual baseband signal having a double frequency interval (2f _int ) is generated. Accordingly, since the maximum frequency of each individual baseband signal is equal to or less than the frequency interval f _int / 2, by setting the sampling frequency f _s of each A / D converter to twice the frequency interval f _int , This means that a sampling frequency f _s that is four times or more the maximum frequency of the baseband signal is set, and as a result, it is possible to perform oversampling twice.

  In addition, this invention is not limited to the said embodiment, For example, the following modifications can be considered.

(1) In the first and second embodiments, the frequency-multiplexed signal F is frequency-converted to the baseband signal. However, the present invention is not limited to this, and the frequency number may be converted to an intermediate frequency signal. However, in this case, it is necessary to perform frequency conversion so as to satisfy the sampling theorem. That is, the maximum frequency of the individual baseband signal after the frequency conversion must be made equal to or less than ½ of the frequency interval _fint . Again, of course, the center frequency of the individual baseband signals, it is prerequisite that a natural number multiple of the sampling frequency f _s.

(2) In the second embodiment, the case where double oversampling is performed has been described. However, the present invention is not limited to double, and oversampling that is two times or more can be similarly performed. For example, when it is desired to perform oversampling of 3 times, three systems of frequency conversion means comprising a mixer and a local signal generator are prepared, and in system 1, individual baseband signals u1, u4, u7,. in system 2 separate baseband signal u2, performs u5, u8 ... discrimination, the system 3 dedicated baseband signal u3, u6, u9 ... discrimination by performing the frequency interval of each line, the f _int 3 Doubled. Therefore, by setting the sampling frequency f _s of each A / D converter to 3 times the frequency interval f _int , a sampling frequency f _s that is 6 times or more the maximum frequency of each individual baseband signal is set. As a result, it is possible to perform oversampling three times.

For example, when four times oversampling is desired, four systems of frequency conversion means comprising a mixer and a local signal generator are prepared. In system 1, individual baseband signals u1, u5, u9,. The system 2 discriminates the individual baseband signals u2, u6, u10..., The system 3 discriminates the individual baseband signals u3, u7, u11... And the system 4 the individual baseband signals u4, u8. , U12..., The frequency interval of each system becomes four times f _int . Therefore, by setting the sampling frequency f _s of each A / D converter to 4 times the frequency interval f _int , a sampling frequency f _s that is 8 times or more the maximum frequency of each individual baseband signal is set. As a result, four times oversampling can be performed.

(3) Although the first and second embodiments have been described as the receiving device in the wireless communication system, the present invention is not limited to this and can be applied to a receiving device in a wired communication system.

1 is a configuration block diagram of a receiving device according to a first embodiment of the present invention. It is a frequency characteristic figure of the individual baseband signal u1-un in 1st Embodiment of this invention. FIG. 3 is a configuration explanatory diagram of a frequency multiplexed signal F when the individual line signal k2 is thinned out in the first embodiment of the present invention. FIG. 3 is a block diagram of a configuration of a receiving apparatus when an individual line signal k2 included in a frequency multiplexed signal F is thinned out. It is a block diagram of the configuration of the receiving device in the second embodiment of the present invention. It is a principle explanatory drawing of 2 times oversampling in a 2nd embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of a frequency multiplexed signal F. It is a 1st structural example of the conventional receiver. It is a 2nd structural example of the conventional receiver.

Explanation of symbols

A ... antenna, B, B1, B2 ... mixer, C, C1, C2 ... local signal generator, D1-Dn ... band pass filter, E1-En ... A / D converter, G ... digital signal processor, F ... frequency Multiple signal

Claims (5)

An apparatus for receiving a frequency-multiplexed signal in which individual line signals having a predetermined bandwidth are arranged continuously or discontinuously at a certain frequency interval equal to or greater than the bandwidth,
Receiving means for receiving the frequency-multiplexed signal;
P units are provided in parallel corresponding to P groups obtained by extracting the individual line signals from the frequency division multiplexed signal every (P-1) (P is an integer of 2 or more). The predetermined individual line signal is a low frequency signal having a center frequency that is a natural number multiple of the frequency interval, or a low frequency signal having a center frequency larger than the center frequency and satisfying the sampling theorem. A frequency converting means for converting the frequency of the frequency multiplexed signal;
Filtering means for selectively discriminating individual low frequency signals corresponding to individual line signals from the low frequency signals as individual received signals;
A plurality of A / D conversion means for sampling each of the individual low frequency signals at a P times oversampling frequency corresponding to P times the frequency interval;
Signal processing means for performing predetermined reception processing on the output signals of the respective A / D conversion means;
A receiving apparatus comprising: The frequency converting means converts the frequency multiplexed signal into a low frequency signal so that the individual line signal of the lowest frequency in each group becomes an intermediate frequency signal that satisfies the baseband signal or the sampling theorem. The receiving device according to claim 1 . A received signal processing method for performing signal processing by receiving a frequency multiplexed signal in which an individual line signal having a predetermined bandwidth is continuously or discontinuously arranged at a constant frequency interval equal to or greater than the bandwidth,
A first step of receiving the frequency multiplexed signal;
P units are provided in parallel corresponding to P groups obtained by extracting the individual line signals from the frequency division multiplexed signal every (P-1) (P is an integer of 2 or more). The predetermined individual line signal is a low frequency signal having a center frequency that is a natural number multiple of the frequency interval, or a low frequency signal having a center frequency larger than the center frequency and satisfying the sampling theorem. A second step of frequency-converting the frequency multiplexed signal;
A third step of selectively discriminating individual low frequency signals corresponding to individual line signals from the low frequency signals as individual received signals;
A fourth step of performing A / D conversion by sampling each of the individual low frequency signals at a P-times oversampling frequency corresponding to P times the frequency interval;
And a fifth step of performing a predetermined reception process on the digital signals after each A / D conversion. In the second step, the frequency-multiplexed signal is frequency-converted into a low-frequency signal so that the individual line signal having the lowest frequency in each group becomes an intermediate frequency signal that satisfies the baseband signal or the sampling theorem. 4. A received signal processing method according to claim 3, wherein: A transmission device for transmitting a frequency-multiplexed signal in which individual line signals having a predetermined bandwidth are continuously or discontinuously arranged at a certain frequency interval equal to or greater than the bandwidth;
Communication system characterized by comprising a receiving device according to claim 1 or 2.

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