KR20030006782A - Expanding Method Of CDMA Demodulation Range And That Apparatus - Google Patents

Abstract

PURPOSE: A method and a device for extending a demodulation range in CDMA(Code Division Multiple Access) are provided to facilitate the handling of a wide-range demodulation area generated during the movement of a service area, even in a restricted demodulation range operated by being set in a multiple access communication system such as CDMA. CONSTITUTION: A starting step(110) arranges a receiving range extending function. An operation variable setting step(120) sets up an operation variable necessary for extending the receiving range. A delayed signal superiority transmitting step(130) generates delayed signals and combines the delayed signals to be stronger than original signals, then transmits the combined signals. A delayed signal superiority stabilizing step(140) allows a receiving party to distinguish the superiority of the delayed signals to move a receiving reference point. A step(150) of searching signals adjacent to the delayed signals searches adjacent signals standardized on the delayed signals and moves the reference point to a signal superior to a searched result. A delayed signal inferiority transmitting step(160) strengthens the original signals and makes the delayed signals weaker than the original signals, to combine and transmit the signals. A delayed signal inferiority stabilizing step(170) moves the reference point of the delayed signals to a reference point of the original signals. A step(180) of searching signals adjacent to the original signals moves the receiving reference point to another adjacent superior signal standardized on the reference point of the delayed signals. An end deciding step(190) decides an operation end. If the operation end is not decided, the step 130 is repeated. And if the operation end is decided, an ending step(199) ends the receiving range extending function.

Description

Expanding Method Of CDMA Demodulation Range And That Apparatus}

The present invention relates to a method for demodulating signals over multiple paths in a multiple access communication scheme such as CDMA.

Conventionally, a multi-path transmission signal of the CDMA has a plurality of reception detection units and searches for a new path signal in a range of a peripheral time band centered on the dominant signal to participate in data demodulation. In case of delay difference exceeding the range of Walsh Code modulated to Pseudo Noise, it is difficult to recognize as signal of same base station, resulting in extremely poor communication status or disconnection.

SUMMARY OF THE INVENTION The present invention provides a method and apparatus for smoothly processing a wide range of demodulation areas occurring when a service area moves despite a limited demodulation range that is established and operated in a multiple access communication method such as CDMA.

1 is a flowchart illustrating a method for extending a CDMA demodulation range according to the present invention.

2 is an example of an environment requiring CDMA demodulation range extension.

3 is a graph of signal crossover and demodulation region movement according to the present invention;

4 is a block diagram of an embodiment of an apparatus for expanding a demodulation range according to the present invention;

Explanation of symbols for the main parts of the drawings

Drawing 1

110: start step 120: operating variable setting step

130: delay signal dominance transmission step 140: delay signal dominance stabilization step

150: signal search step near the delay signal 160: delayed signal transmission step 13

170: deferred stabilization of delayed signal 180: search for neighboring signals of original signal

190: End judgment step 199: End step

Drawing 2

210: CDMA base station 220: reflector

230: mobile station 240: relay station

250: natural terrain reflector 260: direct path

270 reflection path

Drawing 3

310: original signal 320: delayed signal

T1: Delayed signal predominant transmission period T2: Delayed signal preponderance transmission period

S: original signal via direct path

D-S: Delayed Signal Through Direct Path

R-S: original signal through the reflection path

R-D-S: delayed signal through the path of reflection

Drawing 4

401: input signal 420: signal distribution unit

430: signal delay unit 440: first gain control unit

450: time control unit 460: second gain control unit

470: signal combination unit 480: output signal

The principle and apparatus configuration of the present invention for achieving the above object will be described with reference to the drawings.

1 is a minimal procedure diagram for realizing the present invention, and will be described with reference to FIGS. 2 and 3 for ease of understanding.

First, the starting step is to install an apparatus or a program for expanding the demodulation area of the present invention.

The operation variable setting step 120 is a step of setting a delay time required for operation of the present invention, and storing variables such as an alternating operation time and an output ratio between the dominant signal and the low signal in the apparatus or program of the present invention.

In the delay signal dominance transmission step 130, the original signal is divided into two or more, and one of the signals is delayed by the time specified in the operation variable setting step 110, and the delayed signal is the strongest component of the output signal component. Combining the signals by a method of adjusting the strength of the other divided signal so as to be possible, and corresponds to the start step of T2 in FIG.

In the delayed signal dominance stabilization step 140, when the strength of the delayed signal and the original signal is changed by the delayed signal dominance step 130, the CDMA receiver selects the most dominant signal within the reception demodulation range as a reference signal. Perform a series of actions. For this reason, the CDMA receiver side adjusts the center point of the reception demodulation range based on the delayed signal.

The neighbor signal search step 150 of the delay signal demodulates and searches the surrounding signals on the basis of the time adjusted in the delay signal dominance stabilization step 140. At this time

In the case of the boundary point where the mobile station 230 of FIG. 2 moves from the CDMA base station side to the reflector 220, the original signal received from the reflector 230 (RS) is directly from the CDMA base station as shown in the case # 1 of FIG. It is superior to the coming delay signal DS. Accordingly, the receiver of the mobile station 230 moves the reference point to the original signal RS coming from the reflector 230 and again moves back to the delay signal RDS coming from the reflector 230. You can successfully move to a signal in an area that extends beyond.

Next, in the delay signal inferiority transmitting step 160, as a transmission procedure relative to the delay signal predominant transmission step 130, the original signal is divided into two or more and one signal is divided into the operation variable setting step 110. Combining the signals by a method of adjusting the strength of the delay-divided signal so that the delayed signal is delayed by a time specified in FIG. 3 and the original signal becomes the strongest component of the output signal components. Corresponding.

In the delayed signal deterioration stabilization step 170, when the strength of the delayed signal and the original signal is changed by the delayed signal deterioration transmission step 160, the CDMA receiver selects the signal that is most dominant in the reception demodulation range as a reference signal. Perform a series of actions. For this reason, the center point of the reception demodulation range is adjusted based on the original signal at the CDMA receiving side.

In the neighbor signal search step 180 of the original signal, the demodulated search is performed based on the time reference adjusted in the delayed signal deterioration stabilization step 140. At this time

In the case of the boundary point where the mobile station 230 of FIG. 2 moves from the reflector 220 to the CDMA base station side, the delay signal DS coming directly from the CDMA base station is received from the reflector 230 as in the case of FIG. The original signal is superior to RS. Therefore, the receiving section of the mobile station 230 moves the reference point with the delay signal DS coming from the CDMA base station, and can be moved back to the original signal S coming from the CDMA base station, thus extending from the original possible area of demodulation reception. The move can be executed successfully with the signal of the reserved area.

Therefore, in the wireless environment between the CDMA base station and the reflector 220 exceeding the range of simultaneous demodulation, the reception demodulation can be successfully performed by applying the present invention to which direction the mobile station 230 moves.

In the following procedure, if it is not an operation stop condition in the operation termination determination step 190 for the relay device of the present invention, the process moves back to the delay signal predominant transmission step 130 and performs the start step 110 and the operation setting step 120. Repeatedly executes the above-described series of operations, and stops the delay operation and passes the original signal prototype when the conditions of the end judgment set in the start step 110 and the operation variable setting step 120 are met. ).

Next, an embodiment of a configuration of a CDMA demodulation range extension apparatus according to the present invention will be described with reference to FIG.

First, the input signal 410 is a CDMA signal corresponding to a base station transmission or a signal received from a mobile station.

The signal distributor 420 is a means for dividing the original signal 410 to add multiple delay elements to the input signal, and typically uses an RF divider.

The signal delay unit 430 generates a time delayed signal (D-S of FIG. 3) than the original signal 410 by using a delay element such as a digital filter composed of a saw filter or a memory.

In the first gain adjuster 440, the delayed signal received from the signal delay unit 430 (DS of FIG. 3) is used to determine the forces of the signals of the delay signal dominance period (T2 of FIG. 3) and the thirteen period (T1 of FIG. 3). A device such as a voltage control attenuator is used as a means of controlling gain by adding or subtracting gain, and the series of control is controlled by the time controller 450.

In the second gain adjusting unit 460, the original signal received from the signal distribution unit 420 (S in FIG. 3) is also used for the signals in the delay signal dominance period (T2 in FIG. 3) and the thirteenth period (T1 in FIG. 3). As a means of controlling gain by adding or subtracting gain in order to create a force, a series of controls are controlled by the time control unit 450 and the first gain control unit 440. There is a characteristic that the deceleration procedure is relatively performed.

In the signal combiner 470, the ratio of the constituents of each signal is controlled by the first gain adjusting unit 440 and the second gain control unit 450 as a means for synthesizing the delayed signal 320 and the original signal 310. Are synthesized.

The output signal 480 is used as a base station transmitter output signal or base station receiver input signal as the CDMA output signal of the signal combiner 470.

The time controller 450 is a means for controlling the gain controllers 440 and 460 by storing the algorithm of the present invention. The time controller 450 is generally configured as a microprocessor or a simple digital system, and remote online control is also possible for convenience of operation. .

It should be noted that the above-described method and application of the present invention are not intended to limit the use of the present invention as an embodiment, but are for explanation to help understanding, and similar examples may be sufficiently applied using the above-described information. will be.

According to the present invention, by artificially expanding the reception demodulation range of CDMA, the reception reference time transition can be effectively performed for a long distance multipath having a natural topography or a relay base station as a reflector. In particular, it is possible to improve the communication quality of the CDMA communication system operating the mobile station, and in the environment where the CDMA communication speed is faster, the demodulation reception range is further reduced, thereby preventing communication quality degradation.

Claims (5)

In the code division multiple access (CDMA) transmission and reception, the original signal is divided and a delay is generated in one of the divided signals, and the non-delayed signal among the divided signals is equal to the delayed signal and has a constant signal size. Method and apparatus for extending the reception range by transmitting and receiving a signal that periodically cross-couples the superiority to The procedure of the receiving range expansion method of claim 1 generates a start step (110) for installing a reception range expansion function and an operation variable setting step (120) for setting operation variables necessary for expansion of a reception range, and a delay signal, and generates a delay signal. Delay signal dominance transmission step 130 for strongly mixing and transmitting and delay signal dominance stabilization step 140 for moving the receiving reference point by sufficiently distinguishing the delayed signal and the adjacent signal based on the delay signal Neighbor signal search step 150 of the delayed signal to search and move the reference point to a signal that is superior to the search result, and delayed signal inferior transmission step of strengthening the original signal and transmitting the delayed signal weakly combined with the original signal. ) And delay signal stabilization step 170 and the circle for moving the delay signal reference point to the reference point of the original signal. In the case of the non-operation decision, the end signal search step 180 and the end decision step 190 of determining the end of the operation of the original signal, which moves the reception reference point to another nearby predominant signal based on the signal of? Method and device for demodulation range expansion, characterized in that the termination step (199) to repeat the execution of the predominant transmission step 130 and terminate the reception range expansion function if the operation is terminated 2. The method and apparatus of claim 1, wherein the transmission output of the CDMA demodulation range expansion device outputs the combined ratio of the delayed signal and the non-delayed original signal periodically and repeatedly. 2. The apparatus of claim 1, wherein the reception range extension device receives a CDMA signal and distributes the signal to the multiple delay generation means. The signal delay unit 430 holds and delays one of the divided signals in time. And a first gain control unit 440 and a second gain control unit 460 and the gain control unit for adjusting a component ratio between the delayed signal and the non-delayed signal to cross-generate the right / lower ratio of the periodic and repetitive signal. A device comprising a time control unit 450 as a means and a signal combiner 470 as a means for combining the generated signal into one output. In each of the claims, A program and method for configuring the receiving range expanding apparatus, and a storage device and a recording medium storing the contents of the program.