KR20010073657A - Dynamic select apparatus and method of phase equalizer in bs receiver - Google Patents

Abstract

PURPOSE: A device and a method for dynamically selecting a phase equalizer in a base station receiver are provided to install equalizers to sequentially change the equalizers, and to select an equalizer indicating the most excellent demodulation characteristic, so as to effectively compensate phase distortion. CONSTITUTION: Switching units(230,231) select one of signals delivered from equalizers(220,221) positioned in an IF(Intermediate Frequency) processor, to switch the selected signal to an A/D(Analog-to-Digital) signal converter, according to a selection signal from a baseband processing unit. A selection unit(250) outputs the selection signal, for selecting an equalizer having the most excellent demodulation characteristic, to the switching units(230,231), according to a demodulation characteristic measured in a demodulator(240) of the baseband processing unit.

Description

DYNAMIC SELECT APPARATUS AND METHOD OF PHASE EQUALIZER IN BS RECEIVER}

The present invention is currently in use wireless subscriber network (WLL), broadband wireless subscriber network (B-WLL), radio frequency network (TRS), mobile telephone network (Cellullar), personal mobile communication network (PCS), intelligent transportation network (ITS), foreign countries Precise phase distortion in wireless communication networks, including other mobile phone networks in use in the world, and next-generation mobile networks such as International Mobile Telecommunication (IMT-2000) and Universal Mobile Telecommunication Service (UMTS), which are currently being standardized in European and North American ways. A computer-readable recording device of a phase equalizer dynamic selection device and a method thereof and a program for realizing the method in a base station digital receiver for selecting analog multi-stage equalizers to more accurately compensate for characteristics to eliminate analog phase errors. To a recording medium.

Recently, with the development of the communication field, mobile communication users want to receive more information and better quality service at a lower price. Thus, mobile communication systems have been switched from analog to digital in order to handle more capacity.

In a mobile communication system, a limited frequency is used within a certain region, and the amount of information required and the number of users requesting use are increasing. Therefore, in order to satisfy such a demand, a method with high frequency utilization efficiency is required among digital methods. Digital mobile communication schemes that are commonly used now include Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA).

Previous studies have shown that the CDMA method is more efficient than the TDMA method in terms of frequency utilization efficiency. In comparison with the TDMA method, the CDMA method uses a wider frequency band.

On the other hand, the domestic digital mobile communication method currently in service is a CDMA method in which the subscriber divides the bandwidth of 1.25MHz into user codes. The signal used in the analog method is a narrowband signal of a frequency modulation (FM) method having a bandwidth of 30KHz.

Recently, as the amount of communication information required for a mobile communication system has exploded due to the demand for multimedia services including the Internet, the amount of data required for one subscriber also reaches several megabits per second (Mbps). The next generation mobile communication (IMT-2000) system, which is being recently researched and developed, also adopts a wideband CDMA method using a bandwidth of 5 MHz to 20 MHz.

Problems that have been neglected in conventional narrowband systems may be raised as problems that cannot be ignored in wideband systems. By using broadband among these problems, the difference in phase characteristics according to the frequency in the bandwidth used is not linear, thereby degrading signal reception performance. The difference in phase characteristics causes inter-symbol interference (ISI) during signal demodulation, which increases the signal-to-noise ratio of the digital system and ultimately degrades the demodulation performance of the receiver.

The difference in phase delay with frequency in the bandwidth used is caused by various causes throughout the system. Differences in the system structure and component characteristics of each terminal and base station manufacturer are caused.

In order to solve the phase delay problem, the current 1.25MHz CDMA system uses an analog phase equalizer for the intermediate frequency (IF) processing of the base station. The phase equalizer compensates the distortion of the signal by intentionally applying a reverse distortion to offset the phase distortion caused by the phase delay, but the phase distortion characteristics may be different because the manufacturers of the terminal and the base station may be different. In such a situation, when the equalizer having one specific phase compensation characteristic fixed to the base station IF processing unit is compensated for in the conventional manner, the equalizer may be operated so that the distortion becomes more severe. This greatly affects the reception characteristics of the receiver. In particular, in the case of a high-speed service such as a data service that requires a relatively wide bandwidth, a more serious problem may occur because the required call quality is higher than that of a conventional voice service.

In addition, the conventional analog implementation method measures the phase characteristics of the representative terminal transmitter and the base station receiver and compensates for the correction with the fixed characteristic values in the base station receiver.

However, such a method cannot be regarded as having the same phase characteristics when the terminal of the terminal measuring the phase of the terminal is different from the terminal of a different company. Therefore, when the base station corrects the same characteristics for the terminals having different phase distortion characteristics, it may result in weight distortion, which reduces the reception performance at the base station. Currently, a base station of a CDMA system (IS-95 based) is implemented in such a structure.

1 is a configuration diagram of a base station receiver for compensating for phase distortion in a conventional wireless communication system, and shows an implementation example of a method of analog processing by an intermediate frequency (IF) processor.

As shown in Figure 1, the signal received by the antenna is amplified by the base station reception RF (Radio Frequency) processing unit 101 and converted to an intermediate frequency (IF) signal by converting the band pass filter and frequency down-converted, then the receiving IF processing unit The analog signal is converted into a digital signal through an equalizer 102 having a fixed characteristic by separating into I (ortho) and Q (orthogonal) channels through a band pass filter and an automatic gain amplifier. The converted digital signal is input to the baseband processor through an I, Q data multiplexer. The input digital signal is demodulated by the demodulator 103 to extract data.

In this way, the equalizer is used as a software processing method, and various equalizer algorithms have been developed in this regard. However, this method has a problem that as the amount of digital signal processing increases, the load of the base station digital processing unit is excessively weighted, thereby increasing the price and the complexity of the structure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and installs a plurality of specific equalizers in the base station receiver to sequentially change the equalizers in a call setup step, and selects an equalizer that exhibits the best demodulation characteristics and phases. SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for dynamically selecting a phase equalizer in a base station receiver for effectively compensating for distortion, and a method thereof and a computer-readable recording medium having recorded thereon a program for realizing the method.

1 is a block diagram of a base station receiver for compensating for phase distortion in a conventional wireless communication system.

2 is a block diagram of an embodiment of a phase equalizer dynamic selection apparatus in a base station receiver according to the present invention;

3 is a flowchart illustrating a method for dynamically selecting a phase equalizer in a base station receiver according to the present invention.

* Explanation of symbols for the main parts of the drawings

210: RF processing unit 220 ~ 221: equalizer

230 ~ 231: Selection switch 240: Demodulator

250: equalizer selector

The present invention for achieving the above object is, in the phase equalizer dynamic selection apparatus of the base station receiving unit of the wireless communication system, which is transmitted from a plurality of equalizers located in the intermediate frequency (IF) processing unit in accordance with the selection signal from the baseband processing unit; Switching means for selecting one of the signals and switching to an analog / digital (A / D) signal converter; And selection means for outputting the selection signal to the switching means for selecting an equalizer having the best demodulation characteristic according to the demodulation quality measured by the demodulator of the baseband processor.

In addition, the present invention is a phase equalizer dynamic selection method applied to a base station receiver of a wireless communication system, comprising: a first step of installing a plurality of equalizers in an intermediate frequency processor; A second step of measuring demodulation quality of the reverse preamble signal received at the base station in the demodulator for all prepared equalizers in order to retrieve all of the plurality of equalizers and storing the demodulation quality in the equalizer selector; And a third step of adjusting the selection switch by selecting an equalizer having the highest quality among the equalizers of which the demodulation quality is measured.

In addition, the present invention, the base station receiving unit of the wireless communication system, the function of installing a plurality of equalizers in the intermediate frequency processing unit; Measuring demodulation quality of the reverse preamble signal received from the base station in the demodulator for all prepared equalizers in order to retrieve all of the plurality of equalizers and storing the demodulation quality in the equalizer selector; And a computer-readable recording medium recording a program for realizing a function of adjusting a selection switch by selecting an equalizer having the highest quality among the equalizers whose demodulation quality is measured.

The present invention guarantees a better communication quality characteristic by enabling a simple structure for correcting the phase distortion characteristic more accurately and economically realizing it.

To this end, first, the base station receiver needs to measure accurate phase distortion characteristics, and second, the base station receiver must minimize the processing load increase.

Third, the structure, software, and standardized radio access standard (base station-terminal term), which are already widely used, must be implemented without modification in order to be applied to the system currently being serviced.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of an embodiment of a dynamic equalizer of a phase equalizer in a base station receiver according to the present invention.

As shown in FIG. 2, the structure until the signal received by the RF processor 210 enters the equalizer has the same structure as that of the system of FIG. 1, and the signal is selected equalizer 220. And through the analog / digital (A / D) signal converter through the selection switches 230 to 231 and are input to the baseband processor. The demodulator 240 measures the demodulation quality of the signal received through the selected equalizer 220, and transmits the quality measurement result to the equalizer selector 250.

Accordingly, the equalizer selector 250 sequentially converts the plurality of equalizer selectors using a control line. Do this for all equalizers. The result is stored in the equalizer selector 250, and the stored equalizer selector 250 selects the equalizer having the best demodulation quality (n-th combination of 220 to 221) and uses the demodulated channel. Therefore, the signal demodulated through the call channel uses an optimal equalizer.

3 is a flowchart illustrating a method of dynamically selecting a phase equalizer in a base station receiver according to the present invention.

As shown in FIG. 3, when a terminal attempts to make a call in an idle state or calls a terminal from a base station (301), the base station transmits a channel allocation forward preamble signal to the terminal (302).

Subsequently, the terminal receiving the channel assignment message establishes a channel and transmits a reverse preamble signal to the base station (303).

Thus, when the base station starts receiving the reverse preamble signal, the demodulator sequentially measures the demodulation quality for all the prepared equalizers in order to search for all the equalizers and stores them in the equalizer selector (304).

As such, when the measurement of all the equalizers is finished, the selection switch is adjusted by selecting the equalizer having the best quality among the equalizers whose demodulation quality is measured (305).

The following process is implemented according to the call control method as in the conventional method. That is, it transmits a forward null traffic signal (306) to cause the base station to transmit a base station response message (307), transmits a reverse null traffic signal (308), negotiates a service option, and enters a call state (309).

Here, the reason for using the reverse preamble signal to measure the demodulation quality is that the preamble is all zero data without including the quality indicator, so it is advantageous to determine the quality in the demodulator, and the time when the preamble signal is transmitted is not the talk time. This is because there is no deterioration in call quality due to replacement of the equalizer.

In the present invention, the selection switch 230 is positioned between the equalizer 220 and the analog / digital signal converter of the IF processor so that one analog / digital signal converter can be used. In addition, in the present invention, the equalizer 220 is positioned at the final stage of the IF processing unit because it is most efficient to remove all the accumulated analog phase errors immediately before the digital unit.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

As described above, the present invention firstly arranges different types of equalizers in a base station receiving IF processing unit to ensure accurate compensation of phase distortion characteristics, and measures the quality characteristics of each equalizer in the baseband processing unit. It is effective to choose the most suitable one.

Second, the present invention has an effect of reducing the signal processing burden of the baseband processor by compensating the phase with only the baseband processor. Therefore, this equalizer optimization selection method uses idle time and idle data (reverse preamble) only when setting up a call channel to set up a call, so that an additional processing time delay or a burden in a call channel state can be reduced. have.

Finally, when the system is implemented by the present invention, the phase distortion of the reverse signal (the direction transmitted from the terminal to the base station) is reduced, and the inter-symbol interference is reduced. This improves the reception characteristics of the base station baseband, and as a result, the frame error rate (FER) of the base station receiver is reduced. At this time, the base station allows the terminal to lower the power of the terminal through the closed-loop power control, which can reduce the noise to other users as much as it can increase the capacity of the entire system. In addition, since the transmission power of the terminal is reduced, the consumption of the battery of the terminal is reduced, and there is an effect of allowing a longer time to be talked on a single charge.

Claims (5)

A phase equalizer dynamic selection apparatus of a base station receiver of a wireless communication system, Switching means for selecting one of signals transmitted from a plurality of equalizers located in an intermediate frequency (IF) processor and switching the analog / digital (A / D) signal converter according to a selection signal from the baseband processor; And Selection means for outputting the selection signal to the switching means for selecting an equalizer having the best demodulation characteristic according to the demodulation quality measured by the demodulator of the baseband processor; Phase equalizer dynamic selection device in the base station receiving unit comprising a. The method of claim 1, The selection signal is, A phase equalizer dynamic selection apparatus of a base station receiver, characterized in that the transmission to the switching means using a reverse preamble signal. A phase equalizer dynamic selection method applied to a base station receiver of a wireless communication system, A first step of installing a plurality of equalizers in the intermediate frequency processing unit; A second step of measuring demodulation quality of the reverse preamble signal received at the base station in the demodulator for all prepared equalizers in order to retrieve all of the plurality of equalizers and storing the demodulation quality in the equalizer selector; And A third step of selecting an equalizer having the highest quality among the equalizers of which the demodulation quality is measured and adjusting a selection switch; Phase equalizer dynamic selection method in the base station receiving unit comprising a. The method of claim 3, wherein The selection switch adjustment process of the third step, A method for dynamically selecting a phase equalizer in a base station receiver, characterized in that the selection switch is adjusted using a reverse preamble signal. In the base station receiver of the wireless communication system, Installing a plurality of equalizers in the intermediate frequency processing unit; Measuring demodulation quality of the reverse preamble signal received from the base station in the demodulator for all prepared equalizers in order to retrieve all of the plurality of equalizers and storing the demodulation quality in the equalizer selector; And A function of adjusting the selection switch by selecting the equalizer having the highest quality among the equalizers whose demodulation quality is measured. A computer-readable recording medium having recorded thereon a program for realizing this.