APPARATUS FOR SELECTING CDMA REVERSE LINK SIGNAL
TECHNICAL FIELD
The present invention relates to an apparatus for selecting CDMA (Code Division Multiple Access) reverse signals by adjusting a level converter in enable/disable mode so that a desired FA (Frequency Assignment) can be applied to a modem chip. In particular, an apparatus for selecting CDMA reverse signals by adjusting CDMA reverse signals transmitted to an LF (Intermediate Frequency) board by means of a signal level converter having a plurality of level conversion devices, i.e., by activating a level conversion device of only a desired FA and disabling the remaining level conversion devices to receive corresponding FA signals and supply the signal to the modem chip. By doing so, the modem chip is capable of receiving signals of a desired FA and demodulating them, and thus the invention can improve various utilizations of a system and selection of a usable FA when establishing the system.
BACKGROUND ART
In a general mobile communication system, it has been an essential function of a modem chip to select an FA in a base station, which adopts various FAs. However, the essential function has not been embodied in conventional systems.
Thus, in order to supply only a desired FA to a modem chip, it is essential that the level conversion devices are adjustable in enable/disable mode to activate the level conversion device of a desired FA and receive corresponding FA signals, where the reverse signals transmitted to an IF board are separated to each FA.
DISCLOSURE OF THE INVENTION
The object of the present invention is to provide an apparatus for selecting CDMA reverse signals by adjusting CDMA reverse signals transmitted to an IF board by means of a signal level converter having a plurality of level conversion devices, that is, by activating a level conversion device of only a desired FA and disabling the remaining conversion devices to receive signals of the corresponding FA and supply the signals to the modem chip. By doing so, the modem chip is capable of receiving the signals of the desired FA and demodulating the same, and subsequently the invention can improve various utilizations of a system and selection of a usable FA when establishing the system.
To accomplish said object, the apparatus of the present invention comprises: a modem for demodulating the CDMA reverse signals; a data line as a pathway for receiving the CDMA reverse signals; a signal level converter having a plurality of level conversion devices for changing levels of the received CDMA reverse signals; a signal line as a pathway which is used for controlling the signal level converter to select an FA (Frequency Assignment); and a PLD (Programmable Logic Device) for controlling the operation of the signal level converter through the signal line and generating signals to select the received signals.
Further, to accomplish the object of the present invention, one among the plurality of level conversion devices is activated and the other conversion devices are disabled in response to the control signal generated by the PLD, and thereafter, a corresponding FA signal is applied to the modem through the data line.
According to the present invention, CDMA reverse signals transmitted to an IF board are adjustable by means of a signal level converter having a plurality of level conversion devices, that is, only a level conversion device of a desired FA is activated and other conversion devices are disabled to thereby receive signals of the corresponding FA and supply the signal to the modem chip. By doing so, the modem chip has the advantage of receiving the signals of the desired FA and demodulating the same. Further, the invention can improve various utilizations of a system, and also provide enhanced system performance by means of selecting a usable FA when establishing the system by correcting contents of the PLD.
BRIEF DESCRIPTION OF DRAWING Fig. 1 shows a block diagram of an apparatus for selecting CDMA reverse signals according to the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
The preferred embodiment of the present invention according to the above- mentioned technical features of the present invention is described below, together with drawings.
Fig. 1 shows a block diagram of the apparatus for selecting CDMA reverse signals according to the present invention.
As shown, the inventive apparatus comprises modem 100 for demodulating CDMA reverse signals, PLD 200 for generating signals to select receiving signals, data line 300 as a pathway for receiving the CDMA reverse signals, signal line 400
as a signal pathway for controlling a signal level converter to select a FA, and signal level converter 500 including a plurality of signal conversion devices for changing . levels of the received CDMA reverse signals.
In other words, modem 100 is a block for demodulating the CDMA reverse signals, PLD 200 is a block for generating signals to select the receiving signals, data line 300 is a pathway for receiving the CDMA reverse signals, signal line 400 is a signal pathway for controlling the signal level converter to select FA, and signal level converter 500 changes the levels of the received CDMA reverse signals and comprises a plurality of level conversion devices. In particular, as illustrated in Fig. 1, signal line 400 is used to control signal level converter 500. Further, only one among three level conversion devices 510, 520 and 530 is activated, and the remaining ones are disabled in response to the signal generated by PLD 200, and subsequently, the corresponding FA signal is applied to modem 100 through data line 300 thereby achieving the advantage of FA selecting.
Further, PLD 200 also includes a function capable of appropriately selecting FA depending on circumstances and conditions of the base station.
Since the present invention was described with respect to a particular embodiment of the apparatus of selecting CDMA reverse signal, it will be apparent - to those skilled in the art that many changes and modifications may be made without departing from the scope of the invention as defined in the appended claims and those equivalent thereto.