Multicarrier signal processing apparatus
A technology of multi-carrier signal and processing device, applied in modulation carrier system, multiplexing communication, multi-frequency code system, etc., can solve the problems of wide frequency band and flat frequency characteristics of analog RF system
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no. 1 approach 〕
[0057] FIG. 5 is a diagram showing the configuration of the second transmitter 2 of the present invention.
[0058] As shown in FIG. 5 , the second transmitter 2 has a configuration in which a digital filter unit 120 is added to the first transmitter 1 shown in FIG. 1 .
[0059] In addition, in the configuration of the transmitter 2 shown in FIG. 5 , the parts that are substantially the same as the configuration of the transmitter 1 shown in FIG. 1 are given the same reference numerals.
[0060] Figure 6 It is a diagram illustrating the configuration of the digital filter unit 120 shown in FIG. 5 .
[0061] Such as Figure 6 As exemplified in , the digital filter unit 120 of this example is a FIR (Finite Impulse Response) filter, and is composed of delay units 122 - 1 to 122 - m , multipliers 124 - 1 to 124 - m , and an adder 126 .
[0062] Hereinafter, a specific example in which the FIR filter 120 is used as the digital filter unit 120 will be described.
[0063] Delay ...
no. 2 approach 〕
[0079] In this example, details of the transmitter 2 of the first embodiment will be described.
[0080] The band limiting filter 102 is an FIR filter that inputs a complex (I, Q) baseband signal, performs filtering with a route roll off characteristic on the I and Q components respectively, and outputs it, and implements a filter frequency such as Improve interpolation processing and image reduction by n times.
[0081] The quadrature modulator 104 converts the complex baseband signal input from the band limiting filter 102 by cos(2πf j ), sin(2πf j ), (i=1··n) represents the complex multiplication result of the local signal as I component, Q component output. That is, each output of the quadrature modulator 104 is modulated by each baseband signal with n intermediate frequencies f i the result of.
[0082] The modulated wave synthesis unit 106 adds the outputs of the quadrature modulation unit 104 to the I and Q components, respectively, and outputs them.
[0083] Modul...
no. 3 approach 〕
[0106] Since the analog processing block 14 ( FIGS. 1 and 5 ) is composed of analog circuit elements such as resistors, capacitors, coils, diodes, transistors, and ICs, it has temperature-dependent characteristics in addition to frequency-dependent characteristics.
[0107] Therefore, even if the influence of the frequency characteristic of the analog processing block 14 ( FIG. 5 ) is mitigated as in the above-mentioned first embodiment, when the ambient temperature changes, the frequency characteristic of the analog processing block 14 may also change and the influence cannot be sufficiently alleviated.
[0108] Therefore, the third transmitter 3 sets the coefficient (filter coefficient) of the FIR filter 120 according to the temperature, and alleviates the influence of the temperature dependence of the analog processing block 14 .
[0109] FIG. 9 is a diagram showing the configuration of the third transmitter 3 of the present invention.
[0110] As shown in FIG. 9 , the thir...
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