KR100327417B1 - Apparatus and method for power estimation of reverse link pilot channel - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to next generation mobile communications, and more particularly, to an apparatus and method for estimating power of a reverse pilot channel, which is suitable for estimating power of a reverse pilot channel. The apparatus for estimating power of a reverse pilot channel according to the present invention includes a receiver for receiving a pilot channel and outputting an I signal and a Q signal, a despreader for despreading the output I and Q signals, and the despreading. A synchronization accumulator for multiplying and multiplying the obtained I signal and the Q signal by a phase signal having a different phase for a predetermined period, and an energy adding unit for adding up energy of signals obtained by multiplying the same phase signal among the accumulated signals; An asynchronous accumulator which accumulates each summed energy, a first comparator which compares each accumulated value accumulated in the asynchronous accumulator, and outputs a large value, and an accumulated value output from the first comparator; Comprising a second comparison unit for determining whether to capture the received pilot channel by comparing the set threshold value pilot information and power control information together There is an effect that can accurately estimate the power of the transmitted pilot channel.

Description

Apparatus and method for power estimation of reverse link pilot channel

TECHNICAL FIELD The present invention relates to next generation mobile communications, and more particularly, to an apparatus and method for estimating power of a reverse pilot channel, which is suitable for estimating power of a reverse pilot channel.

In a code division multiple access (CDMA) communication system based on IS-95A, a pilot channel provides information such as time and phase synchronization to a receiver. This pilot channel is an unmodulated spread spectrum signal transmitted by a CDMA channel transmitted from a base station, and the mobile station performs various signal processing functions such as forward link acquisition, signal tracking, and handoff using the pilot channel.

At this time, the channel searcher of the mobile station finds the PN code offset through acquisition of the pilot channel.

1 is a block diagram of a channel searcher used for capturing a conventional pilot channel.

Referring to FIG. 1, the conventional channel searcher receives a signal and outputs an I signal and a Q signal, a PN sequence generator 108 generating a PN code, and an I output from the receiver 100. A despreader 101 for despreading by multiplying the PN code generated by the PN sequence generator 108 with the signal and the Q signal, and accumulating an I signal despread and output from the despreader 101; A coherent accumulator 102, a second coherent accumulator 103 that accumulates the Q signal despread and output from the despreader 101, and the first synchronous accumulator 102; And an energy summing unit 104 for summing the energy of the I signal and the Q signal output from the second synchronous accumulator 103 and an asynchronous accumulating the energy of the I signal and the Q signal summed in the energy summing unit 104. Accumulator 105 and the value accumulated in the asynchronous accumulator 105 Comparing the specified threshold comprises a comparator 106 for determining whether the initial acquisition of the pilot channel, the controller 107 that controls each device.

The operation of the channel searcher configured as described above is as follows.

First, in a communication system based on IS-95A, the channel searcher is provided in the mobile station because the pilot channel is supported only on the forward link.

When the pilot channel is received from the base station, the channel searcher multiplies the local PN codes generated by the PN sequence generator 108 and despreads the signals, and then performs the synchronous and asynchronous accumulation processes on the I and Q signals, respectively. Calculate the accumulated value for.

The comparator 106 compares the calculated accumulated value with a threshold value already set to determine whether to capture an initial pilot channel.

However, in the conventional communication system as described above, since the pilot channel is supported only on the forward link, only the pilot signal is transmitted on the pilot channel.

In contrast, in a next-generation mobile communication system such as the IS-2000, a pilot channel is supported on the reverse link, and thus, the pilot channel muxes the power control bit in addition to the pilot signal as shown in FIGS. 2A and 2B. As a result, the conventional channel searcher cannot determine whether a pilot channel has been acquired.

In more detail, in the next generation mobile communication system, the pilot channel structure of the reverse link muxes pilot information and power control bits to form one power control group (PCG) of 1.25 ms. At this time, the pilot information is 1 PCG Inserted for time, and the power control bits Is inserted for hours.

Therefore, when the base station acquires a pilot channel in units of one PCG, if it is determined whether the pilot channel is acquired with a different accumulated PN offset as shown in FIG. Since other information is inserted during the time, the base station cannot perform accurate channel acquisition.

Therefore, there is a demand for a channel estimating apparatus capable of capturing a reverse pilot channel in a next generation mobile communication system.

Accordingly, an object of the present invention is to provide a power estimation apparatus and method for a reverse pilot channel capable of acquiring a reverse pilot channel, which is made in view of the above-mentioned problems of the prior art.

According to an apparatus feature of the present invention for achieving the above object, the power estimation device of the reverse pilot channel includes a receiver for receiving a pilot channel and outputting an I signal and a Q signal, and the inverted I and Q signals A despreading unit for spreading, a synchronous accumulating unit for multiplying the despreaded I signal and a Q signal by multiplying a phase signal having a different phase for a predetermined period, and energy of signals from which the same phase signal is multiplied among the accumulated signals An energy summing unit for summing each, an asynchronous accumulating unit for accumulating each of the summed energies, a first comparing unit for comparing each accumulated value accumulated in the asynchronous accumulating unit, and outputting a large value; And a second comparator that compares the accumulated value output from the first comparator with a preset threshold and determines whether the received pilot channel is captured.

Preferably, the first accumulator for multiplying the I signal output from the despreader and the first multiplier for multiplying the I signal output from the despreader with a phase signal having a different phase; A second synchronous accumulator for accumulating the I signal output from the one multiplier, a third synchronous accumulator for accumulating the Q signal output from the despreader, and a phase signal having a different phase to the Q signal output from the despreader And a fourth synchronous accumulator for accumulating a Q signal output from the second multiplier.

According to the method feature of the present invention for achieving the other object as described above, the power estimation method of the reverse pilot channel receives the pilot channel and outputs the I signal and the Q signal, and despread the output I signal and Q signal do. Subsequently, the despread I and Q signals are divided into two signals, and any one of the divided signals is multiplied by a phase signal having a different phase for a predetermined period, and then each of the divided signals is synchronized and accumulated. do. The energy of the signals multiplied by the same phase signal is summed asynchronously from each of the synchronous accumulated signals, and then a large value is selected by comparing the asynchronous accumulated accumulation values with each other. Thereafter, comparing the selected value with a predetermined threshold value, and determining whether to capture the received pilot channel.

1 is a block diagram of a channel searcher used for capturing a conventional pilot channel

2A and 2B are diagrams illustrating the structure of a reverse pilot channel supported in a next generation mobile communication system.

2C is a diagram illustrating a power control group (PCG) used in channel estimation in a next generation mobile communication system.

4 is a block diagram illustrating a channel searcher according to the present invention.

* Description of the symbols for the main parts of the drawings *

400 receiver 401 despreader

402, 403: multipliers 404 to 407: synchronous accumulator

408, 409: energy summing unit 410, 411: asynchronous accumulator

412, 413: comparator 414: controller

415: PN Sequence Generator

Hereinafter, a configuration and an operation according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

The present invention proposes a power estimation apparatus and method for a reverse pilot channel capable of capturing a reverse pilot channel at a base station when the pilot channel is supported over a reverse link as in a next generation mobile communication system.

To this end, the present invention multiplies and accumulates the despread I and Q signals by multiplying phase signals having different phases for a predetermined period in consideration of transmission of pilot information and power control information through a reverse pilot channel. In other words, within one PCG Pilot information has been inserted for the time Considering that the power control bit is inserted for a time During time, a synchronous accumulation process is performed by multiplying phase signals having different phases.

Subsequently, the energy summing process and the asynchronous accumulation process are performed separately for the signals multiplied by the phase signal having the same phase in consideration of the power control bit being 1 or -1.

Thereafter, a large value is selected from the accumulated values of each of the asynchronous accumulation processes performed, and it is determined whether to capture the reverse pilot channel by comparing it with a threshold that is already set.

4 is a block diagram illustrating a channel searcher according to the present invention.

Referring to FIG. 4, the channel searcher according to the present invention receives a signal and outputs an I signal and a Q signal, a PN sequence generator 415 for generating a PN code, and a receiver in the receiver 400. A despreader 401 for despreading by multiplying the output I signal and the Q signal by the PN code generated by the PN sequence generator 415, and an I signal despread and output from the despreader 401. Accumulate a first synchronous accumulator (404), a first multiplier (402) for multiplying a phase signal with an I signal despread from the despreader (401), and in the first multiplier (402). A second synchronous accumulator 405 that accumulates the output I signal, a third synchronous accumulator 406 that accumulates the Q signal output by being despread from the despreader 401 and an inverse spreader 401. A second multiplier 403 for multiplying a phase signal by a spread Q signal and a second multiplier A fourth energy accumulator 407 that accumulates the Q signal output from the device 403 and a first energy sum that sums energy of signals output from the first and third sync accumulators 404 and 406. A second energy summing unit 409 for summing the energy of the signal output from the second synchronous accumulator 405 and the fourth synchronous accumulator 407, and the first energy summing unit 408. A first asynchronous accumulator 410 for accumulating the energy of the signal summed at the second signal, a second asynchronous accumulator 411 for accumulating the energy of the signal summed at the second energy adding unit 409, and the first asynchronous accumulator. The first comparator 412 outputs a large value by comparing the accumulated value at 410 with the accumulated value at the second asynchronous accumulator 411, and the accumulated value outputted at the first comparator 412 and the already set value. A second comparator 413 for comparing the thresholds to determine whether an initial acquisition of a pilot channel is made; It consists of a controller 414 that controls the devices.

The operation of the channel searcher configured as described above is as follows.

First, the signal received at the antenna is input to the receiver 400, and the receiver 400 processes the received signal and outputs an I signal and a Q signal.

The despreader 401 then multiplies the I and Q signals output from the receiver 400 by multiplying the PN codes generated by the PN sequence generator 415. Here, the PN sequence generator 415 generates a PN I code for despreading the I signal and a PN Q code for despreading the Q signal.

The despreader 401 then outputs the despread I and Q signals, and the first synchronous accumulator 404 accumulates the I signal output from the despreader 401. At this time, the first multiplier 402 multiplies the phase signal by the I signal output from the despreader 401. This phase signal is from one PCG group Have the same phase for the rest of the time During time they have different phases.

like this The reason for multiplying phase signals with different phases over time is that the power control bits have a value of 1 or -1. That is, when the power control bit has a value of 1 Synchronous accumulation can be achieved with signals having the same phase even during time, and when the power control bit has a value of -1, By accumulating synchronously with a signal with a different phase only during time, accurate accumulation can be obtained regardless of the power control bits.

Therefore, by multiplying this phase signal before the synchronous accumulation process, When the channel search using only the pilot information lasted for a period of time is not completed, it is possible to prevent the search result performed until that time from being used.

Therefore, the second synchronous accumulator 405 accumulates the I signal multiplied by the phase signal in the first multiplier 402, and the third synchronous accumulator 406 accumulates the Q signal output from the despreader 401, The fourth synchronous accumulator 407 accumulates the Q signal multiplied by the phase signal in the second multiplier 403.

Subsequently, the first energy summing unit 408 and the second energy summing unit 409 add up the energy of signals multiplied by the same phase information during one PCG.

That is, the first energy adder 408 sums the energy of the signals output from the first synchronous accumulator 404 and the third synchronous accumulator 406, and the second energy adder 409 is the second synchronous accumulator. 405 and the energy of the signals output from the fourth synchronous accumulator 407 are summed.

Thereafter, the first asynchronous accumulator 410 accumulates the energy summed by the first energy adder 408, and the second asynchronous accumulator 411 accumulates the energy summed by the second energy adder 409. .

Accumulated values accumulated in the first asynchronous accumulator 410 and the second asynchronous accumulator 411 are input to the first comparator 412, and the first comparator 412 is provided with the first asynchronous accumulator 410 and the second comparator. The accumulated values of the paths having a large energy are output by comparing the accumulated values input by the asynchronous accumulator 411. This first comparator 412 finds a path using the same phase signal as the power control bits included in the PCG.

Then, the second comparator 413 compares the accumulated value output from the first comparator 412 with a threshold value already set to determine whether to capture the reverse pilot channel.

As described above, according to the apparatus and method for estimating power of a reverse pilot channel according to the present invention, it is possible to accurately estimate the power of a pilot channel through which pilot information and power control information are transmitted.

In particular, the present invention can estimate the reverse pilot channel of the mobile station supported by the next-generation mobile communication system, such as IS-2000 system in the base station has the effect that can provide a more stable system operation and communication services.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the examples, but should be defined by the claims.

Claims (3)

A receiver for receiving a pilot channel and outputting an I signal and a Q signal; A despreader for despreading the output I and Q signals; A synchronization accumulator for multiplying the despread I and Q signals by multiplying a phase signal having a different phase for a predetermined period; An energy summing unit for summing energy of signals multiplied by the same phase signal among the accumulated signals; An asynchronous accumulator for accumulating the sum of the respective energies; A first comparison unit for comparing the accumulated values accumulated in the asynchronous accumulation unit with each other and outputting a large value; And a second comparator configured to compare the accumulated value output from the first comparator with a predetermined threshold and determine whether the received pilot channel is captured. The method of claim 1, wherein the synchronous accumulation unit, A first synchronous accumulator for accumulating the I signal output from the despreader; A first multiplier for multiplying the I signal output from the despreader with a phase signal having a different phase; A second synchronous accumulator for accumulating the I signal output from the first multiplier; A third synchronous accumulator for accumulating the Q signal output from the despreader; A second multiplier for multiplying a Q signal output from the despreader with a phase signal having a different phase; And a fourth synchronous accumulator for accumulating the Q signal output from the second multiplier. Receiving a pilot channel and outputting an I signal and a Q signal; Despreading the output I and Q signals; Dividing the despread I and Q signals into two signals, multiplying one of the divided signals by a phase signal having a different phase for a predetermined period, and then synchronously accumulating each of the divided signals Wow, Asynchronously accumulating the sum of the energy of signals multiplied by the same phase signal among the synchronous accumulated signals; Comparing the asynchronous accumulated accumulation values with each other to select a larger value; And determining whether to capture the received pilot channel by comparing the selected value with a threshold that is already set.