WO1994027389A1

WO1994027389A1 - Time diversity receiver

Info

Publication number: WO1994027389A1
Application number: PCT/JP1994/000400
Authority: WO
Inventors: Shogo Ito; Yoshiaki Hirai; Toshihiro Nozawa
Original assignee: Ntt Mobile Communications Network Inc.
Priority date: 1993-05-19
Filing date: 1994-03-14
Publication date: 1994-11-24
Also published as: JP2974880B2; JPH06334572A; CA2136182A1; CA2136182C

Abstract

This receiver performs time diversity by use of the output of a wave detector, but does not use any circuit for detecting the level of reception. In this way, the circuit of the receiver is simplified and the power consumption is reduced.

Description

Description Time diversity receiver

〔Technical field〕

The present invention relates to a receiver for performing time diversity reception for performing high quality signal transmission in wireless communication with fusing. INDUSTRIAL APPLICATION This invention is utilized for the receiver in mobile communications, such as a radio selective call.

(Background technology)

Figure 1 shows the configuration of a receiver that performs time diversity reception using a conventional reception level. In this case, the operation on the transmitting side transmits the same code signal a plurality of times.

In FIG. 1, a case where a binary code is received will be described as an example.

The signal received via antenna 1 is input to reception Z demodulator 2 and reception level detector 3. The output signal of the detector output from the reception Z demodulator 2 is sign-determined as binary data (0 or 1) by the sign discriminator 4, and then input to the signal processing unit 6 that performs time diversity processing. The signal of the reception level output from the reception level detector 3 is input to the signal processing unit 6 after being sampled by the AZD converter 5. The signal processing unit 6 compares the received level sample value received this time with the received level sample value of the signal received up to the previous time stored in the memory 7 for each code, and corresponds to the higher received level sample value. Perform time diversity processing to select binary data. Further, after the time diversity reception processing is completed, the signal processing section 6 stores the sample value and the corresponding binary data in the memory 7 and outputs the sample value and the binary data to the terminal 8 as an output. By repeating the above operation, high-quality signal transmission can be realized on a mobile communication transmission line with fusing.

However, as described above, in order to perform time diversity reception processing that can realize high quality transmission, the reception level detector 3 is required, which complicates the circuit and increases power consumption. Was. SUMMARY OF THE INVENTION It is an object of the present invention to provide a time diversity receiver that can reduce the power consumption by eliminating the complexity of the circuit configuration and the cause of the increase in power consumption by the reception level detector in the time diversity receiver. .

[Disclosure of the Invention]

According to the present invention, in a time diversity receiver provided with a time diversity processing means for receiving the same code signal a plurality of times and performing diversity processing, the time diversity processing means detects a signal received by retransmission. A time diversity receiver which performs time diversity reception processing using a detector output and a detector output for a signal received up to the previous time.

The time diversity processing means includes a sampling circuit for sampling the detector output, and a memory for storing the sampled value. The time diversity processing means includes an absolute value of the sampled value of the detector output with respect to the signal received by retransmission and the memory. Means for comparing, for each code, the absolute value of the sampled value of the detector output with respect to the signal received up to the previous time stored in the same received signal, and selecting the sampled value whose absolute value is larger And means for performing the same.

The time diversity processing unit further includes a sampling circuit that samples the detector output, and a memory that stores the sampled value, wherein the time diversity processing unit stores the sampled value of the detector output with respect to the signal received by retransmission, and stores the sampled value in the memory. Means for adding, for each code, the sampled value of the output of the detector with respect to the signal received up to the previous time for the same received signal.

As means for receiving the same code signal a plurality of times, each is composed of n (n is a natural number of 2 or more) subframes of a fixed length, each containing a separate paging signal of the receiver. For a paging signal that is inserted into a subframe located at one end of a frame and has a transmission count of two or more times, repeatedly receives the frame with the configuration inserted in the subframe located at a location corresponding to the number of transmissions Preferably, means are included.

According to the present invention, a radio paging signal in which the same code signal is transmitted a plurality of times is time-diversified. In a time diversity receiver that performs high-quality reception by performing high-speed processing, it performs time diversity processing on the sampled values of the detector output without performing reception level detection, and does not require a reception level detector. .

In the time diversity processing, the absolute value of the sampled value of the detector output of the signal received this time is compared with the absolute value of the sampled value of the detector output up to the previous time, and the larger sample value is selected to select the time diversity. Perform processing. At the same time, the sample value after the time diversity reception processing is written to the memory, and the code is determined for each code.

Also, instead of comparing sample values, time diversity processing by addition processing can be performed.

As described above, in the present invention, since the time diversity reception processing is performed only from the detector output, a circuit related to the reception level detection is not necessary, which simplifies the circuit configuration and reduces the power required for the reception level detection circuit. Since there is no consumption, the power consumption of the receiver can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a conventional time diversity receiver that performs a time diversity reception process by detecting a reception level.

FIG. 2 is a diagram showing a configuration of a time diversity receiver according to the first embodiment and the second embodiment of the present invention.

FIG. 3 is a diagram for explaining the time diversity processing operation for the detector output of the first embodiment. FIG. 3 a shows the detector output for the first received signal, and FIG. 3 b shows the detector output for the second received signal. The detector output is shown.

FIG. 4 is a diagram showing an example of a frame signal format configuration suitable for the embodiment of the present invention. FIG. 4a shows a frame configuration at time s0, and FIG. 4b shows a frame configuration at time s0 + T. .

FIG. 5 is a flowchart showing a time diversity processing operation in the first embodiment of the present invention.

FIG. 6 illustrates the time diversity processing operation for the detector output of the second embodiment. FIG. 7 is a flowchart showing a time diversity processing operation in the second embodiment of the present invention.

[Best mode for carrying out the invention]

(Example 1)

The configuration of the first embodiment of the present invention will be described with reference to FIG. The time diversity receiver of this embodiment includes an antenna 1, a reception Z demodulator 2 for receiving and demodulating a reception signal received via the antenna 1, and an AZD as a sampling circuit for sampling a detector output. It comprises a converter 5, a memory 7 for storing the sample values, a signal processing unit 9 for performing a time diversity process, and a sign determination unit 10. The signal processing unit 9 performs processing on a signal received by retransmission. The absolute value of the sample value of the detector output and the absolute value of the sample value of the detector output with respect to the previously received signal stored in the memory are compared for each code with respect to the same received signal. Means for selecting a sample value whose absolute value is larger, and a sample value after the time diversity reception processing is written to the memory and output to the code determiner 10 for code determination for each code. And a stage.

Next, the operation of the receiver of this embodiment will be described. In this embodiment, a case where a binary code is received will be described as an example.

The signal received via antenna 1 is input to receive Z demodulator 2. The detector output signal output from the reception Z demodulator 2 is sampled for each code in the AZD converter 5, and then input to the signal processing unit 9. The signal processing unit 9 calculates the time divergence Z that satisfies the following equation (1) using the sample value X of the signal received this time for each code and the sample value Y of the same signal received from the memory 7 up to the previous time. Performs the reception process.

I Z I = m a X (| X I, | Y |)… (1)

Further, the signal processing unit 9 stores the sample value Z in the memory 7 and outputs the sample value Z to the sign determination unit 10 after the end of the time diversity reception. In addition, sign decision unit 1 A value of 0 determines the sign of the sample value Z as binary data (0 or 1), and outputs this binary data to the terminal 8. By repeating this operation, high-quality signal transmission can be realized on a mobile communication transmission line with fusing. Note that the code determination operation of the code determiner 10 can be performed by the signal processing unit 9, and in this case, the code determiner 10 does not need to be provided separately.

The operation of this embodiment will be described more specifically with reference to FIG. FIG. 3 is a diagram for explaining an operation of sampling and sampling the detector output signal, comparing the absolute values of the sampled values, and performing time diversity processing.

Assume that the detector output for the first received signal has a waveform as shown in Fig. 3a. This waveform is sampled at a predetermined sampling timing to obtain sample values of Y,, Y ₂ , Υ ₃ ,. The first sample value is stored in the memory 7 and output to the sign determiner 10. Next, it is assumed that the detector output for the second signal has a waveform as shown in Fig. 2b. Sample values sampled for the detector output is _{_{X,, X 2, X 3}} , ... it becomes. The signal processing unit 9, the last sample value stored in the memory _{7 Υ,, Υ 2, Υ} 3, ... absolute value and the current sample value X,, chi _2, chi _3, ... of the absolute value Then, the sample value having the larger absolute value is stored in the memory 7 as Ζ, Ζ ₂ Ζ ₃ ,. When comparing the absolute values of 値, and X, in each comparison, Υ, is larger. Also, the following Υ ₂ and χ ₂ have opposite signs, but the absolute value of X ₂ is larger. Sample value after the time diversity processing Te month that _{_{Ζ,, Ζ 2, Ζ 3}} , ... as the, Ζ, = Υ,, Ζ 2 = Χ 2, Ζ 3 = Χ 3, ... sample value in the memory 7 of It will be remembered.

As a frame signal format in the radio paging system for transmitting the same code signal which is suitable for the time diversity system of this embodiment a plurality of times, the inventors have previously described PCTZ JΡ94 / 00107 or PCTZ JP 94/00289. A method of a paging signal frame that allows the receiver to recognize the number of paging signal transmissions is presented.

An example of this frame signal format shows a frame format having the configuration shown in FIG. Here, for example, a frame having a signal length of “ It is assumed that the line paging receiver first receives the frame at time s0, then receives the frame at time s0 + T, and FIG. 4a shows the frame configuration at time s0, and FIG. 3 shows a frame configuration of s 0 + T. Here, T is the period of the frame.

This frame consists of n fixed-length subframes following the frame synchronization signal. A new frame, one or more paging signals are inserted in the first subframe, and the mth subframe is inserted. The paging signal transmitted at the m-th time is inserted in the frame. Focusing on one paging signal, the position moves by one subframe every frame period. Referring to the examples shown in FIGS. 4a and 4b, if the paging signals A, B, C, and D were inserted in the first subframe of the frame at time s0, these paging signals A, B, and C , D is inserted into the second subframe in the frame at time s0 + T, and into the kth subframe in the frame at time s0 + (k-1) T (where k = l to n). You. Then, the n-th transmission ends at the frame at time s0 + (n-1) T. In other words, the position of the paging signal in the frame in each transmission period changes regularly, and the receiver can predict the position of the paging signal transmitted from the second time onward, and the same paging signal has the same bit configuration. Therefore, when performing the time diversity processing in the signal processing unit 9, the same received signal to be compared can be extracted and compared for each code.

FIG. 5 is a flowchart showing an operation example of the time diversity processing using the frame signal shown in FIG. 4 in the radio paging system of the present embodiment. However, this figure focuses on a subframe containing one and the same signal.

With the time diversity receiver of the above-described embodiment, time diversity reception processing can be performed by applying only the detector output without detecting the reception level.

(Second embodiment)

Next, a second embodiment of the present invention will be described. The configuration of the receiver is the same as that of the first embodiment, and the time diversity receiving process in the signal processing unit 9 is different from that of the first embodiment.

The operation on the transmitting side is described below. The case where the receiver receives a binary code will be described as an example.

The signal received via antenna 1 is input to receive Z demodulator 2. Further, the detector output signal output from the reception Z demodulator 2 is standardized for each code in the AZD converter 5 and then input to the symbol processing section 9. The signal processing unit 9 calculates, for each code, a time diversity reception that calculates 信号 that satisfies the following equation (2) from the sample value X of the signal received this time and the sample value 同一 of the same signal received up to the previous time from the memory 7. Perform processing.

Ζ = Χ + Υ… (2)

Further, after the time diversity reception processing, the signal processing section 9 stores the sample value に in the memory 7 and outputs the sample value に to the sign determination device 10. Further, the sign judging unit 10 judges the sign of the sample value として as binary data, and outputs the binary data to the terminal 8. By repeating the above operation, high-quality signal transmission can be realized on a mobile communication transmission line with fusing.

Next, the operation of the embodiment will be described more specifically with reference to FIG. As in the first embodiment, the detector output for the first received signal has the waveform shown in FIG. 6A. The waveform is sampled at a predetermined sampling timing, obtaining _{_{Y,, Y 2, Y 3}} , ... a sample value of. The first sample value is stored in the memory 7 and output to the sign half-value device 10. Next, it is assumed that the detector output for the second signal has the waveform shown in Fig. 6b. The sampled values of the sampling for the detector output are X, X ₂ , Χ ₃ ,. The signal processing unit 9 performs an addition process on the previous sample values Υ, Υ ₂ , Υ ₃ ,... Stored in the memory 7 and the current sample values X,, χ ₂ , χ ₃ ,. Υ, = Χ. + Υ., Ζ ₂ = Χ ₂ + Υ ₂ , Ζ ₃ = Χ ₃ + Υ ₃ ,..., Are stored in the memory 7 as sample values after the time diversity processing, and the sign decision unit 10 Output to FIG. 7 is a flowchart showing the operation of the time diversity processing using the frame signal shown in FIG. 4 in the radio paging method of the second embodiment. However, this figure focuses on a subframe containing one and the same signal.

Performing reception level detection by the time diversity receiver of the above-described embodiment. And time diversity reception processing becomes possible by applying only the detector output.

In the above-described first and second embodiments, the operation has been described by taking as an example the case of receiving a binary code. However, the present invention is similarly effective when a code of three or more values is received. . In this case, the sign determinator may correspond to the number of code values.

Claims

Scope

1. In a time diversity receiver equipped with time diversity processing means for receiving the same code signal a plurality of times and performing diversity processing,

The time diversity processing means performs time diversity reception processing using a detector output for a signal received by retransmission and a detector output for a signal received up to the previous time. Machine.

2. It has a sampling circuit that samples the detector output, and a memory that stores this sampled value.

The time diversity processing means includes:

The absolute value of the sample value of the detector output with respect to the signal received by the retransmission and the absolute value of the sample value of the detector output with respect to the signal received up to the previous time stored in the memory are taken as the same reception signal. Means for comparing each code,

Means to select the sample value whose absolute value is greater

The time diversity receiver according to claim 1, comprising:

3. It has a sampling circuit that samples the detector output and a memory that stores this value.

The time diversity processing means includes:

Means for adding, for each code, a sample value of a detector output for a signal received by retransmission and a sample value of the detector output for a previously received signal stored in the memory for the same received signal.

The time diversity receiver according to claim 1, comprising:

4. Each frame is composed of η sub-frames (η is a natural number of 2 or more), each of which contains the individual paging signal of the receiver, and a new paging signal is inserted into the sub-frame located at one end of the frame. For paging signals whose number of transmissions is two or more times, means for repeatedly receiving frames with a configuration inserted in a subframe arranged at a location corresponding to the number of transmissions is included. The time diversity receiver according to any one of claims 1 to 3.