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CDMA radio transmission apparatus, CDMA radio reception apparatus, and CDMA radio communication method

a radio transmission apparatus and radio reception technology, applied in the field of cdma radio communication, can solve the problems of limited system capacity, limited cell radius, and inability to improve quality

Inactive Publication Date: 2004-03-11
INVT SPE LLC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

"The present invention relates to a CDMA radio communication system and method that can improve resistance against fading and shadowing to improve signal quality and system capacity. The invention proposes a method of interleaving spread chips to keep the quality of each symbol in a frame constant, while reducing the impact of fading and shadowing. This interleaving can decrease the required transmission power and improve transmission efficiency. The invention also proposes a method to reduce interference between different users and extend the cell radius in a TDD system. Overall, the invention aims to improve the quality and efficiency of CDMA radio communication systems."

Problems solved by technology

However, in the conventional CDMA radio communication system, since spread signals are arranged to be concentrated upon a successive short time in the same frequency, when the short time is affected by fading and shadowing, qualities of all chips in the time deteriorate at the same time, resulting in that the qualities are not improved even though the spreading gain is obtained by despreading.
It thereby results in another problem that the system capacity is limited because the transmission is performed under large transmission power.
Therefore, a guard time corresponding to a propagation delay time is required with the length limited to ensure the transmission efficiency, thereby resulting in the problem that a cell radius is limited.
In this system, since the high rate transmission power control is performed, the user A signal quality is almost constant between slots, however is not always constant due to control delay and error when fading occurs rapidly.
On the other hand, since it is not expected to improve qualities for signals with low qualities with such increment of power, the transmission power is increased in order not to interfere in other users.

Method used

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  • CDMA radio transmission apparatus, CDMA radio reception apparatus, and CDMA radio communication method
  • CDMA radio transmission apparatus, CDMA radio reception apparatus, and CDMA radio communication method
  • CDMA radio transmission apparatus, CDMA radio reception apparatus, and CDMA radio communication method

Examples

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Effect test

embodiment 5

[0093] (Embodiment 5)

[0094] FIG. 16 is a block diagram illustrating a configuration of a CDMA radio communication apparatus according to Embodiment 5 of the present invention.

[0095] In a transmitter, transmission data 1201 is spread at spreading section 1202, and then subjected to chip interleaving processing at chip interleaving section 1207. The interleaved signal is modulated at modulation section 1203, amplified at transmission amplifying section 1204 and then transmitted from transmission antenna 1205.

[0096] In a receiver, a signal received at reception antenna 1211 is detected at detection section 1212, and then subjected to inverse arrangement to the chip interleaving at the transmission side, i.e., deinterleaving, at chip deinterleaving section 1217. The deinterleaved data is combined at maximal-ratio despreading section 1213 to obtain received data 1214. Maximal-ration despreading section 1213 performs weighting on the deinterleaved data based on likelihood estimated form t...

embodiment 6

[0101] (Embodiment 6)

[0102] FIG. 17 is a block diagram illustrating a configuration of a CDMA radio communication apparatus according to Embodiment 6 of the present invention.

[0103] In a transmitter, transmission data 1301 is spread at spreading section 1302, and then subjected to chip interleaving processing at chip interleaving section(CI) 1307. The interleaved signal is modulated at modulation section(MOD) 1303, amplified at transmission amplifying section(TA) 1304 and then transmitted from transmission antenna 1305.

[0104] In a receiver, a signal received at reception antenna 1311 is detected at detection section 1312, and then subjected to inverse arrangement to the chip interleaving at the transmission side, i.e., deinterleaving, at chip deinterleaving section(CD) 1317. The deinterleaved data is combined at despreading section 1313 to obtain received data 1314.

[0105] Further, an arrival time of received data 1314 is measured at synchronization detection section(SYNC) 1316. Tran...

embodiment 7

[0112] (Embodiment 7)

[0113] FIG. 19 is a block diagram illustrating a configuration of a CDMA radio communication apparatus according to Embodiment 7 of the present invention.

[0114] Operations in a transmitter and a receiver are the same as those in Embodiment 6 except that transmission time length control is performed to a user of which arrival time is fast. Based on arrival time information measured from synchronization detection for every user, all users transmission power control section 1501 (herein after referred to as U-TPC section 1501) controls transmission time lengths of all users.

[0115] Operations in the CDMA radio communication apparatus configured as described above is described using FIG. 20.

[0116] In FIG. 20, when it is assumed that the spreading factor is 16 and the total symbol number is N, 0th chips to 15th chips for symbols 0 to N-1 are arranged respectively in user A slots 0 to 15 after chip interleaving. It is further assumed that one frame contains slots 0 to ...

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PUM

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Abstract

A CDMA radio transmission apparatus includes a spreader, a chip interleaver, and a transmitter. The spreader divides one symbol to a plurality of N chips equal to a number of a plurality of N slots contained in a frame, by spreading the one symbol by a spreading factor N equal to the number of the plurality of N slots contained in the frame. The chip interleaver performs a chip interleaving processing, whereby each of the plurality of N chips is equally assigned to each of the plurality of N slots. The transmitter operates to transmit the plurality of N slots in sequence.

Description

[0001] This application is a continuation of U.S. patent application Ser. No. 09 / 359,020, filed on Jul. 22, 9, pending, the contents of which are expressly incorporated by reference herein in its entirely.[0002] 1. Field of the Invention[0003] The present invention relates to a CDMA radio communication system and method in a digital radio communication using the CDMA (Code Division Multiple Access).[0004] 2. Description of the Related Art[0005] FIG. 1 is a block diagram illustrating a configuration of a conventional CDMA radio communication system. In the CDMA radio communication system, at a transmission side, transmission data 1 is spread at spreading section 2. The spread signal is modulated at modulation section 3 and then amplified at transmission amplifying section 4. The resultant signal is transmitted from transmission antenna. An amplitude in transmission amplifier 4 is determined at high rate transmission power setting section 6.[0006] On the other hand, at a reception sid...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): H04B1/69H04B1/707H04B7/26
CPCH04B7/2628H04B1/707Y02D30/70H04B1/69
Inventor KITAGAWA, KEIICHIUESUGI, MITSURU
Owner INVT SPE LLC