JP4343065B2 - Wireless communication apparatus and wireless communication control method - Google Patents

Description

  The present invention relates to a multiband and multimode radio communication apparatus and radio communication control method applicable to a plurality of radio frequency bands and a plurality of radio communication systems.

  Conventionally, multiband and multimode wireless communication apparatuses that can be applied to a plurality of wireless frequency bands and a plurality of wireless communication systems with a single wireless communication apparatus have been studied. For example, in the prior art 1 described in Patent Document 1, a set of a down-converter mixer and a local frequency signal generation circuit (synthesizer or frequency divider) is provided for each radio frequency band, and is matched to the target radio frequency band. The corresponding group is switched by a switch. In the prior art 2 described in Patent Document 2, only one downconverter mixer is provided in common, and the received signal and the local frequency signal input to the downconverter mixer are switched by a switch.

Non-Patent Document 1 describes a technique (conventional technique 3) for realizing multi-sampling by allocating a common sampling clock to a plurality of systems.
JP 2001-186042 A JP 2000-124829 A Ryo Sawai and three others, “Adaptive Multisampling Processing Method for Multimode / Multiservice Software Wireless Communication System”, IEICE Transactions, July 2001, B Vol. J84-B, No. 7, p. 1187-1197

  However, in the prior arts 1 and 2 described above, the operation of the wireless communication device is fixed to the wireless communication system specification to be used by switching the switch according to the wireless frequency band to be used during actual use. Wireless communication in a plurality of radio frequency bands and a plurality of wireless communication systems cannot be performed simultaneously.

  For these reasons, it is desired to realize a wireless communication apparatus that can perform wireless communication in a plurality of wireless frequency bands and a plurality of wireless communication systems at the same time by applying the multi-sampling technique of the above-described conventional technique 3. .

  The present invention has been made in view of such circumstances, and its purpose is to apply multi-sampling technology to simultaneously perform radio communication in a plurality of radio frequency bands and a plurality of radio communication systems. And a wireless communication control method are provided.

  In order to solve the above-described problem, a wireless communication apparatus according to the present invention performs frequency conversion in which time conversion is performed for each wireless communication system with respect to a reception signal in which wireless signals of a plurality of wireless communication systems are mixed. Means, analog-digital conversion means for uniformly sampling at one sampling frequency with respect to a signal that is time-division multiplexed signals of the plurality of radio communication systems after frequency conversion, and demodulation means for each radio communication system, Switching means for switching the demodulating means to which the sampling data is output, and instructing the frequency conversion means to switch the frequency conversion target system, and the switching in synchronization with the switching timing of the frequency conversion target system. And a control means for giving a switching instruction to the means.

  In the wireless communication apparatus according to the present invention, the control unit performs switching of the frequency conversion target system prior to the sampling timing so that the input signal of the analog-digital conversion unit is determined by the sampling timing. Features.

  In the wireless communication apparatus according to the present invention, the control means includes an unstable period due to switching of the frequency conversion target system and a delay time from the switching timing of the frequency conversion target system to the input timing of the analog-digital conversion means. It is characterized in that the preceding time is added for the time taken into account.

  The radio communication control method according to the present invention includes a process of performing frequency conversion in a time division manner for each radio communication system on a reception signal in which radio signals of a plurality of radio communication systems are mixed, A process of uniformly sampling a signal for time division multiplexing of a signal of a radio communication system at one sampling frequency, and a demodulator that serves as an output destination of the sampling data from among the demodulator for each radio communication system And a process of instructing switching timing of the frequency conversion target system and instructing switching of the demodulating means in synchronization with the switching timing of the frequency conversion target system.

  According to the present invention, by multi-sampling using one sampling frequency by one analog-to-digital conversion means, signals of a plurality of wireless communication systems are digitized while being time-division multiplexed simultaneously, and the digitized time-division multiplexing is also used. The signal of each wireless communication system in the signal can be distributed to the demodulation means for each wireless communication system. Thereby, each demodulation process is performed by the demodulation means for each wireless communication system to obtain a demodulated signal of each wireless communication system, and at the same time, wireless communication in a plurality of wireless frequency bands and a plurality of wireless communication systems can be performed. Can be done.

  In addition, by switching the frequency conversion target system prior to the sampling timing so that the input signal of the analog-digital conversion means is determined by the sampling timing, a transient signal state due to switching of the frequency conversion target system is avoided. And good sampling can be performed.

Hereinafter, embodiments of the present invention will be sequentially described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a wireless communication apparatus 1 according to the first embodiment of the present invention. 1 is an example of a superheterodyne receiver. The wireless communication device 1 is configured to be able to simultaneously receive and demodulate wireless signals of N (N is an integer of 2 or more) wireless communication systems.

  In FIG. 1, an antenna 101 receives each radio signal of the first to Nth radio communication systems. A signal received by the antenna 101 is input to the band pass filter 102, and signals in bands outside the range of each radio frequency (RF) band used in the first to Nth wireless communication systems are blocked, and the amplifier The signal is amplified by 103 and input to the mixer 104.

  The mixer 104 multiplies the input signal from the amplifier 103 by the local signal B input from the local signal generator 117, and outputs a signal resulting from the multiplication. Here, one of the first to Nth wireless communication systems is selected as a frequency conversion target depending on the frequency of the local signal B. The output signal of the mixer 104 is down-converted to an intermediate frequency (IF) band by passing through the band-pass filter 105.

  The local signal generator 117 changes the frequency of the generated local signal B according to the local control signal A input from the control unit 118.

  The output signal of the bandpass filter 105 down-converted to the IF band is amplified by the amplifier 106, adjusted to a predetermined signal level by the attenuator 107, and input to the quadrature demodulator 111.

  The orthogonal demodulator 111 obtains a baseband signal C by performing orthogonal demodulation on the input signal. The baseband signal C is digitized by an analog-digital converter (AD converter) 112. The AD converter 112 performs sampling using the sampling timing signal D input from the control unit 118. The digitized baseband signal E is input to the switch 113 and is input to one of the demodulator 115 via the switch 113. Demodulators 115-1 to 115-N correspond to the first to Nth wireless communication systems, respectively. The switch 113 switches the demodulator 115 that receives the baseband signal E in accordance with the switching control signal F input from the control unit 118. Demodulators 115-1 to 115 -N demodulate the baseband signal E input thereto.

  The control unit 118 generates a local control signal A, a sampling timing signal D, and a switching control signal F using the master clock generated by the oscillator 119.

2 and 3 are block diagrams showing first and second configuration examples of the local signal generator 117 shown in FIG.
In the first configuration example of FIG. 2, any one of the oscillators 401-1 to 401 -N having a frequency corresponding to each IF used in the first to N-th wireless communication systems and the output signals of the oscillators 401-1 to 401 -N A switch 402 that selectively outputs one signal as the local signal B. The switch 402 switches a signal output as the local signal B in accordance with the local control signal A input from the control unit 118.

  The second configuration example of FIG. 3 includes an oscillator 501 having one frequency and a frequency divider 502 that divides an output signal of the oscillator 501 to generate and output a local signal B. The oscillator 501 generates a signal having a frequency that is a common multiple of the frequency corresponding to each IF used in the first to Nth wireless communication systems. The frequency divider 502 has a variable frequency dividing ratio so that a frequency corresponding to each IF used in the first to Nth wireless communication systems can be generated from the frequency of the output signal of the oscillator 501. Have. Then, the frequency divider 502 changes the frequency division ratio according to the local control signal A input from the control unit 118 and generates the local signal B.

Next, the operation of the wireless communication apparatus 1 of FIG. 1 will be described with reference to FIG.
FIG. 4 is a timing chart for explaining the operation of the wireless communication apparatus 1 shown in FIG. In FIG. 4, for convenience of explanation, the case of receiving wireless signals of two wireless communication systems (systems 1 and 2) is taken as an example, but the case of receiving wireless signals of three or more wireless communication systems. Can be extended in the same way.

  In FIG. 4, a local control signal A indicates a target system that performs frequency conversion from an RF band to a baseband band. Further, the local control signal A is output so that the total period per unit time becomes longer as the transmission rate is higher only during the period according to the transmission rate of the frequency conversion target system. In the example of FIG. 4, the output period of the local control signal A related to the system 1 is three periods per four sampling periods in the AD converter 112. On the other hand, the output period of the local control signal A related to the system 2 is only one period per four sampling periods of the AD converter 112.

  The local signal generator 117 generates the local signal B for the system 1 during the system 1 period of the local control signal A according to the local control signal A, while the system is generated during the system 2 period of the local control signal A. 2 local signal B is generated. The frequency conversion target system is selected by the local signal B, and the AD converter input signal C for the system 1 is generated during the system 1 period of the local signal B. During the period, an AD converter input signal C for the system 2 is generated.

  Note that, at the switching timing of the local control signal A, the local signal B is in a transitional state and an unstable period occurs. For this reason, the input signal C of the AD converter 112 has the unstable period and is added with circuit delays of the respective units 104 to 107 and 111. Considering these unstable periods and circuit delays, the local control signal A is created by the control unit 118 so as to take a timing adjustment time with respect to the sampling timing of the AD converter 112. Specifically, as shown in FIG. 4, the local control signal A is switched before the sampling timing of the AD converter 112. For example, switching to the system 1 is performed at a time T1 ′ before the sampling timing time T1.

  The AD converter 112 samples the input signal C at the sampling timing of the sampling frequency of the sampling timing signal D input from the control unit 118. For example, in the sampling period related to the system 1 at times T1 to T3, three samplings are performed, and three sampling data S1-1, 2, and 3 related to the system 1 are obtained. In the sampling period related to the system 2 at the next time T4, one sampling is performed, and one sampling data S2-1 related to the system 2 is obtained.

  A switching control signal F of the switch 113 indicates a system corresponding to the input signal E. When the output destination of the switch 113 is switched according to the switching control signal F, the input signal E is input to the corresponding demodulators 1 and 2, respectively. In the example of FIG. 4, the input signal E is output to the demodulator 1 for the system 1 during the period of the input signal E related to the system 1. As a result, the sampling data S1-1, 2, 3, 5, 6, 7... According to the system 1 are input to the demodulator 1. On the other hand, in the period of the input signal E related to the system 2, the input signal E is output to the demodulator 2 for the system 2. As a result, the sampling data S2-1, 2, 3,... According to the system 2 are input to the demodulator 2.

  Note that in the demodulator 1 for the system 1, there is a gap in the input sampling data. For example, S1-4 between S1-3 and S1-5 is missing, but this missing value is interpolated. Do. Further, in the system 2, the transmission rate is such that it can be demodulated with the value of sampling once every four sampling cycles.

  Next, the configuration and operation related to the control unit 118 in FIG. 1 will be described with reference to two configuration examples.

FIG. 5 is a block diagram showing a configuration example of the control unit 118 shown in FIG. FIG. 6 is a timing chart for explaining the operation of the control unit 118 shown in FIG. Hereinafter, the control unit 118 of FIG. 5 will be described with reference to FIG.
In FIG. 5, a master clock signal is input from the oscillator 119 to the control unit 118. This master clock signal is output to the AD converter 112 as the sampling timing signal D as it is. The counter 602 is a 2-bit counter and circulates the counter value in the order of 0, 1, 2, 3, 0 in synchronization with the master clock signal (see the counter value in FIG. 6).

  The delay unit 603 delays and outputs the master clock signal (see the delay unit output signal in FIG. 6). This delay time is a time corresponding to the timing adjustment time between the sampling timing and the local signal A in FIG.

  The encoder 604 encodes the counter value of the counter 602 in synchronization with the delayed master clock signal (delayer output signal) delayed by the delay unit 603 (see the encoder output signal in FIG. 6). This encoded value is output as the local control signal A shown in FIG. In the example of FIG. 6, the counter values “0”, “1”, “3” are encoded into values indicating the system 1, and the counter value “2” is encoded into values indicating the system 2.

  A DFF (D type flip-flop) 605 holds and outputs the encoded value of the encoder 604 in synchronization with the master clock signal (see the DFF output signal in FIG. 6). This DFF output signal is output as the switching control signal F in FIG.

FIG. 7 is a block diagram showing another configuration example of the control unit 118 shown in FIG. FIG. 9 is a timing chart for explaining the operation of the control unit 118 shown in FIG. Hereinafter, the control unit 118 of FIG. 7 will be described with reference to FIG.
In FIG. 7, a master clock signal is input from the oscillator 119 to the control unit 118. This master clock signal is used as an operation clock for the counter 702 and the flip-flops 704 and 705. The flip-flops 704 and 705 are flip-flops configured as a JK type, for example, as shown in FIG. The initial value of the flip-flop 704 is 1, and the initial value of the flip-flop 705 is 0.

  The counter 702 is a 3-bit counter with an initial value of 0, and the counter value is cyclically counted in the order of 0, 1, 2, 3, 4, 5, 6, 7, 0 in synchronization with the master clock signal. (Refer to the counter (702) value in FIG. 9).

  The comparator 703 outputs a comparator output signal K1 when the counter value of the counter 702 is “7”, and outputs a comparator output signal K2 when the counter value of the counter 702 is “5” (the comparator output signal of FIG. 9). (See K1 and K2).

  Each time the comparator output signal K1 is input, the flip-flop 704 inverts 0/1 of the output in synchronization with the master clock signal (see the output signal of the flip-flop (704) in FIG. 9). The output signal of the flip-flop 704 is output as the sampling timing signal D.

  Each time the comparator output signal K2 is input, the flip-flop 705 inverts 0/1 of the output in synchronization with the master clock signal (see the flip-flop (705) output signal L in FIG. 9). The output signal L of the flip-flop 705 corresponds to the output signal of the delay device 603 shown in FIG. 5 (the delay device output signal shown in FIG. 6).

  The counter 706 corresponds to the counter 602 of FIG. 5 described above, and counts up by counting the counter values in order of 0, 1, 2, 3, and 0 in synchronization with the output signal of the flip-flop 704, that is, the sampling timing signal D. (Refer to the counter (706) value in FIG. 9).

  The encoder 707 corresponds to the encoder 604 of FIG. 5 described above, and encodes the counter value of the counter 706 in synchronization with the output signal L of the flip-flop 705 (see the encoder output signal of FIG. 9). This encoded value is output as the local control signal A. In the example of FIG. 9, the counter values “0”, “1”, and “3” are encoded into values indicating the system 1 and the counter value “2” is a value indicating the system 2 as in the example of FIG. Is encoded into

  The DFF 708 corresponds to the DFF 605 in FIG. 5 described above, and holds and outputs the encoded value of the encoder 707 in synchronization with the output signal of the flip-flop 704, that is, the sampling timing signal D (see the DFF output signal in FIG. 9). This DFF output signal is output as a switching control signal F.

  As described above, according to the present embodiment, frequency conversion is performed from the RF band to the baseband band in a time-sharing manner for each radio communication system with respect to a reception signal in which radio signals of a plurality of radio communication systems are mixed. A signal (AD converter input signal C in FIG. 4) generated by time-division multiplexing of the baseband signal of the wireless communication system is generated. Then, the time division multiplexed signal is uniformly sampled at one sampling frequency, and the demodulator for each wireless communication system to which the sampling data is output is switched in synchronization with the switching timing of the frequency conversion target system.

  Accordingly, the baseband signals of a plurality of wireless communication systems are digitized while being time-division multiplexed simultaneously by multi-sampling using one sampling frequency by one AD converter 112, and the digitized time-division multiplex baseband is also obtained. The baseband signal of each wireless communication system in the signal can be distributed to the demodulator for each wireless communication system. As a result, each demodulator for each radio communication system performs each demodulating process to obtain a demodulated signal of each radio communication system, and at the same time, radio communication in a plurality of radio frequency bands and a plurality of radio communication systems can be performed. Can be done.

  In addition, since the frequency conversion target system is switched prior to the sampling timing so that the AD converter input signal C is determined by the sampling timing, a transient signal state due to switching of the frequency conversion target system is avoided. Good sampling can be performed. Preferably, it is preferable to precede the unstable period due to the switching of the frequency conversion target system and the time including the delay time from the switching timing of the frequency conversion target system to the input timing of the AD converter.

Next, a second embodiment will be described.
FIG. 10 is a block diagram showing a configuration of a wireless communication device 1a according to the second embodiment of the present invention. In FIG. 10, parts corresponding to those in FIG. 1 are given the same reference numerals, and explanation thereof is omitted.

  The wireless communication device 1a of FIG. 10 is an example of a low-IF type among superheterodyne receivers. In this wireless communication device 1a, a signal digitized by the AD converter 112 after down-conversion from the RF band to the IF band is converted into a baseband signal by the digital orthogonal demodulator 111a. That is, in the present embodiment, the input signal C of the AD converter 112 is time-division multiplexed with signals of IF bands of a plurality of wireless communication systems. In the AD converter 112, the time division multiplexed signal is uniformly sampled at one sampling frequency, as in the first embodiment.

  Next, the sampling data is input to the digital quadrature demodulator 111a and converted into a baseband signal. The demodulator for each wireless communication system that is the output destination of the time division multiplexed baseband signal is switched by the switch 113 in accordance with the switching control signal F, as in the first embodiment. Accordingly, as in the first embodiment, the demodulator for each wireless communication system that is the output destination of the time division multiplexed baseband signal is switched in synchronization with the switching timing of the frequency conversion target system.

  Therefore, also in the second embodiment, the same effect as in the first embodiment can be obtained. In other words, a single AD converter 112 performs digital sampling while simultaneously time-division-multiplexing signals of IF bands of a plurality of wireless communication systems by multi-sampling using one sampling frequency, and orthogonally demodulates the digitized signals. The baseband signal of each wireless communication system in the time division multiplexed baseband signal can be distributed to the demodulator for each wireless communication system. As a result, each demodulator for each radio communication system performs each demodulating process to obtain a demodulated signal of each radio communication system, and at the same time, radio communication in a plurality of radio frequency bands and a plurality of radio communication systems can be performed. Can be done.

  Further, by switching the frequency conversion target system prior to the sampling timing so that the AD converter input signal C is determined by the sampling timing, a transient signal state due to switching of the frequency conversion target system is avoided. And good sampling can be performed. Preferably, it is preferable to precede the unstable period due to the switching of the frequency conversion target system and the time including the delay time from the switching timing of the frequency conversion target system to the input timing of the AD converter.

Next, a third embodiment will be described.
FIG. 11 is a block diagram showing a configuration of a wireless communication device 1b according to the third embodiment of the present invention. In FIG. 11, portions corresponding to the respective portions in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  The wireless communication device 1b in FIG. 11 is an example of a direct conversion type receiver. In this wireless communication device 1b, the quadrature demodulator 111 directly downconverts the RF band to the baseband band. Here, the quadrature demodulator 111 converts the RF band signals of a plurality of radio communication systems into baseband signals by the time division using the local signal B. The time division multiplexed baseband signal is input to the AD converter 112 as an AD converter input signal C, as in the first embodiment. Thereby, also in 3rd Embodiment, the effect similar to the said 1st Embodiment is acquired.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention.

It is a block diagram which shows the structure of the radio | wireless communication apparatus 1 which concerns on the 1st Embodiment of this invention. FIG. 10 is a block diagram showing an example of the configuration of a local signal generator 117. FIG. 12 is a block diagram showing another configuration example of the local signal generator 117. 5 is a timing chart for explaining the operation of the wireless communication apparatus according to the embodiment of the present invention. It is a block diagram which shows the example of 1 structure of the control part 118 which concerns on embodiment of this invention. 6 is a timing chart for explaining the operation of the control unit 118 shown in FIG. 5. It is a block diagram which shows the other structural example of the control part 118 which concerns on embodiment of this invention. FIG. 8 is a block diagram illustrating a configuration example of flip-flops 704 and 705 illustrated in FIG. 7. It is a timing chart for demonstrating operation | movement of the control part 118 shown in FIG. It is a block diagram which shows the structure of the radio | wireless communication apparatus 1a which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the radio | wireless communication apparatus 1b which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Wireless communication apparatus, 104 ... Mixer, 111 ... Quadrature demodulator, 111a ... Digital quadrature demodulator, 112 ... AD converter, 113 ... Switch, 115-1-N ... Demodulator, 117 ... Local signal Generator 118, control unit, 119, oscillator.

Claims (4)

Frequency conversion means for performing frequency conversion in a time division manner for each wireless communication system, with respect to a reception signal in which wireless signals of a plurality of wireless communication systems are mixed,
Analog-to-digital conversion means for uniformly sampling at one sampling frequency for a signal that is time-division multiplexed signals of a plurality of radio communication systems after the frequency conversion;
Demodulation means for each wireless communication system;
Switching means for switching the demodulation means to be the output destination of the sampling data;
Control means for instructing the frequency conversion means the switching timing of the frequency conversion target system, and instructing the switching means to switch in synchronization with the switching timing of the frequency conversion target system;
A wireless communication apparatus comprising:   2. The radio according to claim 1, wherein the control unit switches the frequency conversion target system prior to the sampling timing so that an input signal of the analog-digital conversion unit is determined before the sampling timing. Communication device.   The control means precedes the unstable period due to the switching of the frequency conversion target system and the time including the delay time from the switching timing of the frequency conversion target system to the input timing of the analog-digital conversion means. The wireless communication apparatus according to claim 2, wherein the wireless communication apparatus is a wireless communication apparatus. A process of performing frequency conversion in a time-sharing manner for each wireless communication system for a received signal in which wireless signals of a plurality of wireless communication systems are mixed,
A step of uniformly sampling a signal obtained by time-division multiplexing signals of a plurality of radio communication systems after the frequency conversion at one sampling frequency;
The process of switching the demodulating means that is the output destination of the sampling data from the demodulating means for each wireless communication system,
Instructing the switching timing of the frequency conversion target system and performing an instruction to switch the demodulation means in synchronization with the switching timing of the frequency conversion target system;
A wireless communication control method comprising:

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