WO2002035720A1 - A method of framing pilot and traffic signals in the cdma system and data frame thereof - Google Patents

A method of framing pilot and traffic signals in the cdma system and data frame thereof Download PDF

Info

Publication number
WO2002035720A1
WO2002035720A1 PCT/CN2000/000359 CN0000359W WO0235720A1 WO 2002035720 A1 WO2002035720 A1 WO 2002035720A1 CN 0000359 W CN0000359 W CN 0000359W WO 0235720 A1 WO0235720 A1 WO 0235720A1
Authority
WO
Grant status
Application
Patent type
Prior art keywords
pilot
traffic
signal
method
interference
Prior art date
Application number
PCT/CN2000/000359
Other languages
French (fr)
Chinese (zh)
Other versions
WO2002035720A8 (en )
Inventor
Cosmos Zhang
Daoben Li
Original Assignee
Linkair Communications. Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B7/00Radio transmission systems, i.e. using radiation field
    • H04B7/24Radio transmission systems, i.e. using radiation field for communication between two or more posts
    • H04B7/26Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
    • H04B7/2618Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using hybrid code-time division multiple access [CDMA-TDMA]

Abstract

The present invention discloses a method of framing pilot and traffic signals in the Code Division Multiple Access (CDMA) mobile communication system, and the data frame structure on the basis of the method, which utilizes time division multiplex in the framing pilot and traffic signals, so as to reduce Multiply Access Interference (MAI) therein, and interposes a plurality of idle time slots between the time division multiplexed pilot and traffic signals to decrease Adjacent Cell Interference (ACI) therein. The performance of the system can be improved and thus the capacity of the CDMA system can be increased with the method disclosed by the present invention.

Description

The pilot signal and traffic data frame framing method and the CDMA system

FIELD

The present invention relates to digital mobile communication systems, and more particularly relates to a method for framing a pilot signal and a traffic code division multiple access (CDMA) communication system, and application data frames. BACKGROUND OF THE INVENTION

Code Division Multiple Access (CDMA) technology introduced effectively ease the contradiction between limited frequency band with unlimited users needs, thus code division multiple access (CDMA) mobile communication system, mobile communication is becoming mainstream. In a CDMA cellular mobile communication system, since the user among users and different cells within the cell to obtain respective different code channels using different spreading address code, therefore, for an N-cell cellular mobile communication system, by which the frequency reuse factor of N is a frequency division multiple-access communication system or a time division multiple access communication system is reduced to 1, i.e. each cell can share all bandwidth. Meanwhile, in the CDMA communication system, since the spread spectrum signal bandwidth wider than the other system, it is possible to achieve separation of multipath signals, to obtain a diversity effect. CDMA communication system more and more full use of the directional antenna and voice activation technology. All this makes the CDMA system spectral efficiency is greatly improved over other systems, is about 20 times the frequency division multiple access mobile communication system, a time division multiple access 10 times the mobile communication system.

In the CDMA mobile communication system, a pilot signal as the channel estimation, synchronization and mainly based soft handoff or the like, is essential. Since the pilot signal is present, so that the receiver can efficiently estimate the channel characteristics, in order to apply the demodulated signal to go. The presence of the pilot signal also helps system synchronization is completed, and provide the necessary basis for the key technology CDMA system power control and handover. Thus, the pilot signal is very important in the design of the CDMA system. There are various already framing method pilot signals. For example IS95 and third generation mobile communication system uses CDMA2000 pilot channel method, i.e. the pilot signal and the traffic signals by occupying a different address code, and code division multiplexing to achieve traffic signals. Since the pilot signal must occupy a larger transmission power to achieve better signal reception quality, such as the

IS95 is 20% of the total base station transmit power, and therefore the presence of the pilot channel to service multiple-access interference signal thousands MAI (Multiply Access Interference) and the interference of neighboring cells ACI (Adjacent Cell Interference) are large. On the other hand, the signal power of the traffic channel is also a great deal of MAI for the pilot channel of the cell, and the pair of guide neighboring cell pilot channel ACI. The presence of these disturbances resulting decrease in the capacity of the CDMA system. In the WCDMA standard, the method is called time division using a dedicated pilot channel, which is the pilot signal and the traffic signal time-division multiplexed, which for the CDMA mobile communication synchronization is avoided to some extent MAI between the pilot signal and the traffic signal, but still not reduced ACI between the pilot signal and the traffic. So its performance will still be a considerable impact, especially when mobile users at the cell boundary. SUMMARY

Object of the present invention to provide a novel process for framing code division multiple access CDMA mobile communication system and a pilot signal and data signal traffic frame formed in accordance with the method to solve the above-described prior art present technical problems and defects.

Present invention provides a method of framing is applied to the pilot signal and traffic signal in a CDMA mobile communication system, according to the present invention, it can reduce or eliminate the MAI and ACI pilot signals and traffic signals between, characterized to reduce MAI in that between the pilot and the traffic signal, the present invention uses time-division multiplexing the pilot signal is designed to reduce or eliminate the ACI, according to the present invention by introducing the concept of empty slots in the time division multiplexed a plurality of pilot insertion symbols and traffic signals between the empty slot, to achieve the purpose of reducing the ACI guide between different frequencies and traffic between cells.

CDMA mobile communication system according to the present invention, the guide method of framing the pilot signal and the traffic signal, can be applied to most of the frame structure of the CDMA system design pilot and traffic signals, can effectively reduce the pilot signal ACI MAI between traffic signals and thereby improve system performance. Further according to the invention can save transmission power of the base station and mobile stations, and eventually increase the capacity of the system. BRIEF DESCRIPTION OF DRAWINGS

1 is a schematic view of the accompanying drawings a preferred embodiment of the method according to the present invention. Embodiment of the present invention.

The present invention will be described in detail in conjunction with the accompanying drawings. The present invention discloses a method of framing applied pilot signal traffic signal in code division multiple access mobile communication system, in a frame, a time-multiplexed manner with the pilot signal traffic signals, and time division multiplexing the pilot adding a number of empty slots between the signal and the traffic signal.

In more detail, in order to reduce the MAI between pilot and traffic signals, the present invention employs a time multiplexed manner to design a pilot signal. In this way the interior portion of the time division multiplexing code division multiple access system for reducing a pilot signal and traffic MAI is quite effective. Because time division multiplexing, synchronous CDMA system, but not to the pilot signal and the traffic signal between the address code by distinguishing slot, thereby avoiding mutual interference between pilot and traffic signals. But this is still fundamentally different from the time division multiplexing communication system completely, since the individual for the pilot signal and the traffic signal, the pilot is still implemented by the spread between the frequency spreading signal or the traffic signal, and rely address code to distinguish.

By the above method, to achieve the purpose of reducing or even eliminate MAI between pilot and traffic signals. However, this does not fundamentally solve the problem of ACI between pilot and traffic signals, because the signals of different cells due to the difference of transmission delays, not simultaneously arrive at the receiver at an arbitrary position, resulting in different cell pilot and traffic signal temporally overlap each other, resulting in mutual ACI. Especially when the cell border, ACI has become a major source of inter-cell interference. In the present invention, by introducing the concept of an empty time slot, to achieve the purpose of reducing the ACI between the pilot and the traffic between different cells. I.e., in the design of the signal frame structure, inserted between a number of traffic signals and the pilot signal time multiplexed empty slots, does not transmit any signal power in the empty slot. Number of empty slots depends on the size of the cell, the chip rate of the system and the like. By this simple design the complexity of the minimal impact on the system, however, since there is an empty slot, avoiding the vicinity of the cell boundary between adjacent cells and between the pilot signal traffic, due to different propagation delay caused by overlap in time, causing ACI. When the mobile station is far away from the boundary of the cell, so that the different cells of the transmission delay difference signal exceeds the inserted empty slots, then appear ACI. It will be appreciated, however, since the path loss decay rapidly with distance, interference of the neighboring cells case traffic between the pilot and thus reduced to a very small extent. Thus preclude the use of the method according to the present invention provides greatly suppressed ACI between the pilot and traffic signals, and can readily appreciate that the present invention provides a simple method of control may be acceptable from a neighboring cell the method of the level of interference between pilot and traffic signals. I.e., by increasing the number of empty slots inserted, the interference can be more effectively suppressed. ACI degree is suppressed, may be (1) is calculated by the following equation:

Equation (1) represents the addition of PVP in empty slots and empty slots when the ratio of size without the addition of ACI, R is the cell radius, c is the speed of light, t is the duration of an empty slot, [alpha] is the path loss factor, and generally value between 2-6. From equation (1) can be clearly seen, by increasing the number of empty slots, thereby increasing t, the ratio of F / P will be reduced more effectively so as to achieve the effect of suppressing ACI. Determining the number of empty slots particular, it is necessary according to the size of the cell radius, a compromise between the empty time slot occupancy and its resources for ACI rejection between pilot and traffic signals. The present invention is applicable to the design of the CDMA system forward and reverse channel, but regardless of the dedicated pilot signals or a common pilot signals provided by the method of the present invention are equally applicable. This is because here the difference between the dedicated pilot signal and the common pilot signal is only in respect of each traffic channel, dedicated pilot signals using different spreading codes and addresses common pilot signal using the same spreading code address they preclude the use of the service signals are time-division multiplexing, the present invention is therefore to dedicated pilot signal or the common pilot signal and no significant difference.

1 of the drawings, a specific embodiment of the present invention, examples. It is shown a method according to the present invention a guide is provided and designed pilot signal traffic frame structure. FIG P represents the pilot signal transmitted in the slot, V representing the time slot is a vacant slot, T transmits traffic signals representative of the time slot. More specifically, in the present embodiment, the pilot 128Tc occupied, empty slot occupancy 30Tc, traffic signal occupies 1024Tc. From the present embodiment can be seen that the proportion of empty time slot resources occupied only 2.5% of total resources. IS95 guide the pilot channel compared framing method of the invention reduces the MAI provides 80% of the total energy of the signal on the traffic signal a pilot signal, and 20% of the total energy of the signal to the pilot signal MAI traffic signal. In the system chip rate of 1.2288MHz, ACI cell radius reduction amount between pilot and traffic when 2KM, can be calculated. I.e. the base station and the neighboring local user or a user or a base station within the cell transmission delay of the transmitted signal does not exceed the inserted empty slots, it will not cause ACI between pilot and traffic signals. Only in a cellular system base station or user more outer ACI may cause it to the local user. And because there is a path loss, the power of the interference signal at this time has been reduced by at least 20dB, it can actually be ignored.

The method described in the present invention, those of ordinary skill in the art, may also have more embodiments. The generic principles defined herein may be applied to other embodiments without creativity. Accordingly, the present invention can not be limited to the embodiments shown herein, but disclosed herein consistent with the principles and novel features of the widest range.

Claims

Claims
1, a method of pilot and frame group traffic signal is applied to a code division multiple access (CDMA) communication system, in a frame, uses TDM pilot symbol between traffic signals and to reduce its multiple access interference (MAI, Multiply Access interference) between; characterized in that:
In conducting the time multiplexed pilot inserting a plurality of empty slots and traffic signals between the symbols to reduce inter-cell interference (ACI, Adjacent Cell Interference) therebetween.
2. The method as claimed in framing claim 1, wherein: the number of the empty slot on the chip rate determines the size of the cell radius, system, empty slots of time resources and space utilization suppression of interference for the time slot interval (ACI) between the pilot and traffic signals.
3. The method of framing claimed in claim 1, wherein: the transmission signal power is not within the empty slot.
4. The method of framing claimed in claim 1, characterized in that: by increasing the number of the empty slots, it is possible to more effectively suppress inter-cell interference (ACI).
5. The method of framing claimed in claim 1, wherein: said pilot symbols are dedicated pilot symbols.
6. The method as claimed in framing claim 1, wherein: said pilot symbols are common pilot symbols.
7, is applied to one kind of pilot code division multiple access (CDMA) communication system, traffic data frame frequency signal, wherein a frame, between the time division multiplexing the pilot symbols for the traffic signal to reduce the multiple access interference between (MAI, Multiply Access interference); wherein:
Between the pilot symbols and the time multiplexed traffic signals, further comprising a plurality of sections to reduce interference (ACI, Adjacent Cell Interference) inserted null slots.
The pilot data frame of the traffic signal, wherein 8, as claimed in claim 7: the number of the empty slot on the chip rate determines the size of the cell radius, system, empty time slot resources the occupancy rate and the degree of inhibition of empty slots for inter-cell interference (ACI) between the pilot and traffic signals.
9, as claimed in claim 7, said pilot signal and traffic data frame, wherein: said pilot symbols are dedicated pilot symbols.
10, as claimed in claim 7, said pilot signal and traffic data frame, wherein: said pilot symbols are common pilot symbols.
PCT/CN2000/000359 2000-10-24 2000-10-24 A method of framing pilot and traffic signals in the cdma system and data frame thereof WO2002035720A8 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2000/000359 WO2002035720A8 (en) 2000-10-24 2000-10-24 A method of framing pilot and traffic signals in the cdma system and data frame thereof

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CN 00813632 CN1421070A (en) 2000-10-24 2000-10-24 Method of framing pilot and traffic signals in CDMA system and data frame thereof
PCT/CN2000/000359 WO2002035720A8 (en) 2000-10-24 2000-10-24 A method of framing pilot and traffic signals in the cdma system and data frame thereof
AU1126201A AU1126201A (en) 2000-10-24 2000-10-24 A method of framing pilot and traffic signals in the cdma system and data frame thereof

Publications (2)

Publication Number Publication Date
WO2002035720A1 true true WO2002035720A1 (en) 2002-05-02
WO2002035720A8 true WO2002035720A8 (en) 2003-02-13

Family

ID=4574731

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2000/000359 WO2002035720A8 (en) 2000-10-24 2000-10-24 A method of framing pilot and traffic signals in the cdma system and data frame thereof

Country Status (2)

Country Link
CN (1) CN1421070A (en)
WO (1) WO2002035720A8 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100536447C (en) 2005-10-31 2009-09-02 华为技术有限公司 Up pilot method for restraining interference

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09327073A (en) * 1996-06-07 1997-12-16 N T T Ido Tsushinmo Kk Method for arranging and transmitting pilot channel in cdma mobile communication system
CN1251699A (en) * 1997-03-31 2000-04-26 摩托罗拉公司 Method and apparatus in radio communication system for implementing frequency reuse plan

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09327073A (en) * 1996-06-07 1997-12-16 N T T Ido Tsushinmo Kk Method for arranging and transmitting pilot channel in cdma mobile communication system
CN1251699A (en) * 1997-03-31 2000-04-26 摩托罗拉公司 Method and apparatus in radio communication system for implementing frequency reuse plan

Also Published As

Publication number Publication date Type
CN1421070A (en) 2003-05-28 application
WO2002035720A8 (en) 2003-02-13 application

Similar Documents

Publication Publication Date Title
Prasad et al. An overview of CDMA evolution toward wideband CDMA
US5619493A (en) Spread-spectrum, frequency-hopping radio telephone system with voice activation
US7177298B2 (en) Dynamic channel allocation in multiple-access communication systems
US6185199B1 (en) Method and apparatus for data transmission using time gated frequency division duplexing
US6215777B1 (en) Method and apparatus for transmitting and receiving data multiplexed onto multiple code channels, frequencies and base stations
US7068637B2 (en) Base station and mobile communication system
EP1037491A1 (en) A CDMA cellular communication system and method of access therefor
US5889815A (en) Spread spectrum communication receiver
US5878350A (en) Scheme for controlling transmission powers during soft handover in a CDMA mobile communication system
US20070064666A1 (en) Method of allocating resources and method of receiving the allocated resources in a communication system
USRE36591E (en) Transmission diversity for a CDMA/TDD mobile telecommunication system
US5896368A (en) Multi-code compressed mode DS-CDMA systems and methods
US7151761B1 (en) Code reservation for interference measurement in a CDMA radiocommunication system
US7088688B2 (en) Apparatus and method for randomly controlling time slot of sub-frame in an NB-TDD CDMA system
Ojanpera et al. An overview of air interface multiple access for IMT-2000/UMTS
US6584116B1 (en) Method of transmission in a UMTS mobile telephone network enabling preparation for handover to a GSM cell during a call in a UMTS cell
Dahlman et al. UMTS/IMT-2000 based on wideband CDMA
US5737358A (en) Multiplexed radio communication system
US20030026235A1 (en) Method and apparatus for time-sharing channelization code in a CDMA communication system
US6333926B1 (en) Multiple user CDMA basestation modem
US6967943B1 (en) Time division multiple access radio systems
US6414947B1 (en) Communication network and method of allocating resource therefor
JPH08500475A (en) Discontinuous transmission for seamless handover in Ds-cdma system
JPH09214404A (en) Spread spectrum communication method and device
JPH10107768A (en) Mobile communication method and its system

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 008136327

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application
CFP Corrected version of a pamphlet front page

Free format text: UNDER (71) THE NAME IN CHINESE CORRECTED

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 69(1) EPC OF 27-10-2003

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase in:

Ref country code: JP