4.Introduction to GU SDR BTS

7/28/2019 4.Introduction to GU SDR BTS

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Introduction to GU SDR

Base Stations

GU Product Support Dept.


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2011-10-29 2

Purpose

2011-10-29 2

You are expected to master the following

knowledge after this course

basic concepts and structure of SDR

Types of SDR base stations

SDR hardware boards

Interfaces of SDR base stations


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Contents

Basic Concepts of SDR

Structure of SDR Base Stations

Introduction to BBUIntroduction to RU/RRU

Introduction to Interface between BBU and RU/RRU

Special Functions of SDR Base Stations


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What is SDR (1)

The radio technologies defined by the SDR forum are classifiedinto five levels: HR, SCR, SDR, ISR and USR.

HR hardware radio Tier0. For example, the traditional

single-mode base station.

SCRsoftware choose radio

Feature: Single-mode base transceiver stations of different

modes can be placed together, but they are integrated in terms

of software.


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What is SDR (2)

SDR- Software Defined Radio: you can use the software toselect a demodulation mode, broadband signals or narrowband

signals. ZTE ZDR base station series leads the technologies in

the industry.

Feature: Different radio modes can share hardware, including

RF front end, ADC/DAC and base band processing.


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What is SDR (3)

ISRIdea software radio.

Feature: 1) get rid of the analog RF front end; 2) the whole system can be

controlled by programming except the antenna.

USRUltimate software radio

Feature: 1) it has the function of the ISR; 2) the controlling software should

be standardized. Switch between different radio modes can be finished within

milliseconds.

The ISR cannot be widely used because the technology is not mature.


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What is SDR (4)

SDR and cognitive radio Cognitive radio is an

important technology of

USR. It can perceive the

surroundings, and adjust

the wireless bandwidthand de-modulation mode

accordingly.


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Contents

Basic concepts of SDR


Introduction to BBUIntroduction to RU/RRU




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SDR technology brings changes to base station structure

Significant feature of the SDR software defined radio mode

1 The RF front end processes

signals of multiple radio modes

2 Baseband processes signals

of multiple radio modes

3 Software integration to

unify software versions

SDR technology the system supports

multiple radio modes


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Market drives changes to the base station structure

Green base

station

Cut cost

Structure

A B

Compatible

DWireless

integration,

IP technology

C


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Structure of ZTE SDR base station

Support the distributed structure of BBU and RRU. Fortraditional base stations, BBU and RRU should be in the same

module.

Multi-mode base band pool BBU

Multi-mode RF platform

Adopt IP technology to process internal data stream of the base

station

OMC platformOMCR and OMCB

Unified software platform

The distributed structure of BBU and RRU and R&D on a unified

platform are the core of the SDR base stations. The new structure

meets the demand and technology required by the market.


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ANT

Transceiver

Front end of Rx

Duplex

Multi-

carrier PA

External power PWS220VAC

RRU/RU

BBU

Resource

control board

BBU baseband pool

Fiber

SDR product structure


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SDR product architecture

Distributed base station: RF is distributed remotely

RRU

BBU


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SDR product architecture

Macro base station: BBU and RU are all in the cabinet, which isdifferent from the distributed base station in structure.


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Internal OnlyAdvantage 1 of the SDR architecture BBU and

RRU can be distributed separately

In this mode, both BBU and RRU and maximize theirefficiency. BBU can achieve the maximum integration,

and RRU can focus on the power of itself.

The networking is flexible if the RRU is distributed

remotely. For example, it can support multi-carrier and

indoor distributed coverage. BBU and RRU can be distributed flexibly, which benefit

for compatibility design.


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Advantage 2 of the SDR architecture baseband hardware

Support multiple radio modes Simple design

Powerful processing capability

Easy to manage

Easy to share resources

Cut cost

Easy for evolution of baseband technologies


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Advantage 3 of the SDR architecture independent RF unit

Simplified functions Improved reliability, easy for maintenance

Improved the efficiency of the power amplifier

Optimized heat design, easy for integration

Closer to antenna, hence bigger power

Flexible forms of RU/RRU products

Help to reduce the size and weight of base stations

Cut cost


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Distributed base station: B8200R8860

B8200: powerful BBU

It supports 60 GSM carriers, and support both GSM and

WCDMA.

R8860: dual mode RRU, broadband transceiverIt supports GSM single-mode 6-carrier, or WCDMA single-mode

3-sector, or supports both radio modes at the same time.

ZXSDR BBU ZXSDR RRU

RF

MS

Um

interface

CPRI

Fiber


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Indoor dual-mode macro base station ZXSDR BS8800

Size: main cabinet 950

600

450 mmextension cabinet 700600450 mm

Weight: main cabinet 150Kg

extension cabinet 130Kg

Power: S12/12/12: 1335W

S6/6/6: 825W

Input voltage: -48VDC (-40~ -57VDC)

Transmission mode: the Abis interface supports 8 E1/T1 links

and 1 GE port.

Maximum site configuration: S12/12/12 or O36


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The structure of ZXSDR BS8800

Main cabinet

1650m

m

450 mm

600mm

PDMCabling trough

Baseband

950m

m

PDM

Cabling trough

RF unit

Extension cabinetFan

RU unit

Heat discharge unitVentilation hole

Heat discharge unitVentilation hole


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BBU: baseband unit, which is the same with B8200.

It can contain at most 2 sets of BBU.

RU02: GSM single-mode RF unit

It supports 2 GSM carriers. The BS8800 cabinet can contain 6 RU02

modules. The transmitting power is 20W/40W.

RU60: GU dual mode RF unit. The core part is the same with that of

R8860. It supports 6 GSM carriers or 3 UMTS cells or GU dual-mode

configuration. Cabinet-top transmitting power is 60W.

RU80: GU dual mode RU unit. It is an upgraded version based on

RU60. Cabinet-top transmitting power is 80W.

Indoor dual mode macro base station ZXSDR BS8800


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BS8800 is developed on ZTEs unified platform. The rack

includes the physical cabinet, PDM unit and FAN unit.

BBU and the RU modules all adopt48V DC power supply.

All of the RU modules have the same size and outline.

The fan rotation speed can be adjusted by the software

according to different heat discharge requirements for

different RU modules, thus to lower down noises and achieve

energy efficient.

BS8800 has been used in the products of the three radio

modes, such as GSM, CDMA and UMTS.

Indoor dual mode macro base station ZXSDR BS8800


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Size: 1700600600 mm

Weight: 263Kg

Power: S12/12/12: 1886W

S6/6/6: 1261W

Input voltage: -48VDC (-40~ -57VDC)

Transmission mode: the Abis interface supports 8 E1/T1 links

and 1 GE port.

Maximum site configuration: S12/12/12 or O36

Outdoor dual mode macro base stationZXSDR BS8900


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The structure of ZXSDR BS8900


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Software architecture of the SDR base station OMC software

OMCB OMCR

BSCRNC

SDR


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Software architecture of the SDR base station OMC software 2

OMCB is an operation and maintenance unit to manage NodeB in3GPP. ZTEs SDR base stations support both radio modes of GSM

and WCDMA. Connection mode of the traditional base station: OMCR-

>BSC->BTS; Connection mode of the SDR: OMCB->BTS, OMCR-

>BSC->BTS.

According to the management mode of WCDMA, the board

management, configuration, software downloading and alarms are all

managed by OMCB. In case of the dual-mode, operation and

maintenance tasks of GSM are moved to OMCB, and OMCR manages

GSM related radio configuration and status management.


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Software architecture of the SDR base station OMC software 4

OMCB and OMCR can share the same server or board, but they are

two different programs and there is no direct interaction between them.

Hence, it is necessary to guarantee data consistent manually.

Theoretically, the basic board information is configured on OMCB, and

the logic information is configured on OMCR. If data are inconsistent

between them, we will take the data on OMCB as the reference data.

The main control board of the SDR will keep a copy of all configuration

data of the OMCB. Hence, the data takes effect directly when the SDR

starts, without direct interaction between the SDR and OMCB. Then,

the SDR creates a link to BSC and requests for radio parameters, and

BSC sends the data except configuration information of OMCB to the

SDR. Thus, a complete data configuration table is generated. That is atheoretic process. In practice, it is necessary to modify the data

configuration. For example, modify radio parameters for expansion

projects. Data configuration of OMCB should be compatible with that of

OMCR, otherwise, the SDR cannot respond correctly.


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Introduction to the control panel of the SDR platform

Abis interface: connect to iBSC by FE or E1

FE: direct transmission by IP directly. The protocol stack is shown in

the below figure on the left.

E1: transmission by IP Over E1. The protocol stack is shown in the

below figure on the right.

SCTP

IP

ETH

SCTP

IP

PPP

HDLCMAC


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Media plane of the SDR

The media plane supports transmission by the RTP protocol

The UBPG of SDR and the BIPB of iBSC process RTP data of the

user plane.

CC is responsible for forwarding messages inside the BBU and over

the Abis interface.

CC

UBPGRRU FS iBSC

Forwarding

RTP


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Contents



Introduction to BBU

Introduction to RU/RRU




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Unified hardware platform UTCA

uTCA (Micro Telecommunications Computing Architecture ) is a

simplified version (Micro TCA) of ATCA (Advanced

Telecommunications Computing Architecture). ATCA and MicroTCA

provide various components of different interfaces, different

protocols and different performances for switching. It is a standard

and open structure. ATCA mainly orients to the environment requiring high-capacity and

high-performance, while uTCA orients to the environment requiring

low-capacity and low-performance. uTCA is cost effective and

volume sensitive. uTCA inherits many features of ATCA, includingbasic interconnection topology and management structure.

PCI Industrial Computer Manufactures Group (PICMG for short), is

an organization which has over 800 member companies, including

Intel, Motorola, and ZTE.


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Hardware boards

Control and clock module (CC)

Fabric switching module (FS)(3 or 4 slot)

Site alarm module (SA)(13th slot)

Baseband processing board (BPC/UBPG)(umts/gsm)(3 or 4)

Fan array module (FA)(controled by CC)

Power module (PM)(1+1)

Backplane board (BB)(CC make managements through BB)

PW FS BP

PW FS BP

SA

CC BP

CC BP


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Hardware interfaces

E1: supports 16 E1/T1 links at most

GE: there are two GE interfaces. One is photo-electricexclusively, and the other is electric.

CPRI: One FS has 6 CPRI interfaces. There are two FSat most, hence there are 12 CRPI interfaces at most.

GPS

1CPRI

GEE1 GE

GPS


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Hardware function module CC

Integrate such functions as main control, clock, switching and the

Iub/Abis interface

Physically, the CC does not provide the E1/T1 interface. It connects

E1/T1 to the SA through the backplane of BBU, and the SA provides

the E1/T1 interface.

Support the master/slave mode

Full IP transmission

CC0: It supports internal or external GPS, clock cascaded connection,

and 16 E1 links. It does not support 2MBits clock.

CC2: It does not support internal or external GPS and clock cascaded

connection. It supports 2MBits clock and 8 E1 links.


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Hardware function module FS

It supports the master/slave mode and the load sharing function.

The slot for FS is also compatible for the baseband board.

6 1.25G CPRI optical ports, which support 24TRX (GSM) or

4CS (WCDMA) each.

It does not support master/slave switchover.

For GU dual mode N+6M


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Diagram of FS IQ switching

F

S

U

BP

G

2

Channel 2

Channel 1

RU1, channel 1

RU1, channel 4

RU1, channel 5

RU1, channel 3

RU1, channel 2

RU1, channel 6

UB

P

G

1

RU1, channel 1

RU1, channel 4

RU1, channel 3

RU1, channel 2


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Hardware function module SA/SE

Environment monitoring module

Fan monitor

SA: support 8 channels of E1/T1 signals, 1 RS232 serial port or

1 RS485 interface, 6 input dry contact alarm, and 2 double-

directional dry contact alarm

SE: support 8 channels of E1/T1 signals, 1 RS232 serial port or1 RS485 interface, 6 input dry contact alarm, and 2 double-

directional dry contact alarm

I t l O l


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Hardware function module UBPG

GSM baseband processing module

Responsible for baseband modulation. Downlink: processing upto 12 carriers, speed adaption, channel coding and interleaving,encryption; producing TDMA burst pulse, GMSK/8PSKmodulation; outputting IQ baseband digital signals; sendingpower and frequency control information to RRU for processing.

Responsible for baseband modulation. Uplink: process up to 12carriers; after receiving IQ baseband data from RRU, performdiversity combination for the receiver, digital demodulation(GMSK and 8PSK demodulation, balance), decryption, de-interleaving, channel decoding and speed adaption, and then

sends to the CC board through the Ethernet port.

I t l O l


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Hardware function module FA

Fan monitoring module

Power supply, rotation control and status report

LEDs on the fan subrack

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Hardware function module PM

A single PM provides 16 12V-power supply, which can meet the

power supply requirement of B8200 in full configuration.

Two PMs working in master/slave mode

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Hardware function module backplane

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BBU configuration rules

Board ConfigurationsPower module (PM) 1 PM is configured by default. Decide whether it is necessary to

configure 2 PMs according to the requirement for reliability and cost.

Site alarm module (SA) 1 SA is configured by default.

Control and clock module (CC) 1 CC is configured by default. Select either CC0 or CC2 according to

the clock and E1. Decide whether it is necessary to configure 2 CCs

according to the requirement for reliability and cost.Fabric switch module (FS) Generally, 1 FS is configured, and 2 FSs at most. The quantity

depends on site configuration.

Universal baseband processing

board for GSM (UBPG)

The quantity depends on site configuration.

The slots are compatible for both the BPC and the UBPG.

Baseband processing board

type C (BPC)

The quantity depends on site configuration.

The slots are compatible for both the BPC and the UBPG.

Fan array module (FA) 1 FA only is configured

Site alarm extension board

(SE)

Optional, which depends on the quantity of dry contacts.

It is inserted at Slot 5.

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Contents



Introduction to BBU




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Multi-carrier RU/RRU (1)

The multi-carrier RF modules include three types:

RU60 (60W) , R8860 (60W), and RU80 (80W).

RU/RRU uses multi-carrier technology. IT performs

signal synthesis for multiple carriers. It uses only

one set of boards and PA, and one set of antenna

system. RU60 supports signal synthesis for 6carriers.

The RU/RRU module has only two external

antenna ports. It supports single-transmitting and

double receiving generally. If the cell has over 6

carriers, one port should be reserved to connect

the other RU.

RU/RRU adopts broadband transceiver and

broadband power amplifier.

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RU/RRU is responsible for functions of the

baseband RF interface and the Uu/Um interface.

RU/RRU is responsible for access and radio link

transmission of UE/MS through the Uu/Um

interface, including RF processing,

modulation/demodulation, measurement and report,

power control, receiving diversity, correction,

synchronization, etc.

It connects to BBU through the optical interface by

the CPRI protocol. It implements the following

functions through the optical interface, such as IQ

data transmission, measurement report, RF function

configuration, clock synchronization, etc.

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R8840: 2100M UMTS single mode, cabinet-top transmittingpower: 60w, supporting 4CS (actually, 3CSs are configured to

meet the requirement of 20w/CS.)

R8860: support 850M/900MGU dual-mode or 1800M/1900Msingle mode. Cabinet top: 80w (GMSK), supporting 24TRX or

4CS or 2W+2G or 1W+4G

R8880: 2100M UMTS single mode; cabinet-top output power:

260w, supporting MIMO (2T2R) and 4CS

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y


R8840: support -48VDC, 110VAC, 220VAC

R8860: support -48VDC. It does not support AC power supply

R8880: support -48VDC, 110VAC, 220VAC

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RU/RRU configuration rules

RRU supports at most 4-level cascaded connection. In practice,

however, it is suggested to adopt only 2-level cascaded connectionin networking.

For RRUs in cascaded connection, there is no limit to the position,

sequence, frequency band, and radio mode.

RRUs of different bands share neither antennas nor feeders.

If a backbone physical site (iron tower) is installed with over 3 sets of

RRU, it is necessary to configure 1 BBU nearby the iron tower.

If a backbone physical site (iron tower) is installed with both R8840

and R8860, it is necessary to configure 1 BBU nearby the iron tower.

If the physical site for hole coverage is configured with 1 2 sets ofRRU, it is suggested to connect the fiber from the nearest backbone

BBU, instead of from tower-top backbone RRU.

For multiple sets of RRUs sharing the iron tower, the isolation

between TX/Rx and RX must greater than 30dB.

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RSU60E and R8860E

RSU60E / R8860E uses the ADTR instead of the previous DTR.Compared with RSU60 (80W) /R8860 (80W), they have the same

cabinet-top output power, but the working bandwidth and RF

indices are greatly improved. The bandwidth of a single module

can reach up to 20M (which can be increased to 25M by software

upgrade from December, 2010).

From Oct. 1, 2010, ZTE stops delivering RSU60/R8860, and

deliver RSU60E and R8860E instead.

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RSU60E and R8860E

Difference in names for RSU60/RSU60E

RSU60/RSU60E Remarks

Name defined by

pre-sales

engineers

RSU60

We do not distinguish the new

module and the old one in the

pre-sales stage, and needs not

inform the customer about it.Name configured in

ECCRSU60 RSU60E Add E to distinguish both of them

Name in the

shipping listRSU60 RSU60E

Name in the label RSU60 RSU60EThe label of RSU60 and that of

RSU60E are different.

Name displayed on

NMsRSU60 RSU60E

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RSU60E and R8860E

Names of R8860/R8860E in different systems

R8860 Remarks

Name defined by pre-sales

engineersR8860

Name configured in ECC R8860 GU**8 (DC) R8860 GU**8 (DC/E)Add E to distinguish

both of them

Name in the shipping list

ZXSDR R8860 GU**8 RA

(DC, TX ***MHz-

***MHz)


(DC, TX ***MHz-

***MHz) (V1.10)

Name in the label


(DC, TX ***MHz-

***MHz)


(DC, TX ***MHz-

***MHz)

No difference for

labels of

R8860 (but

different in

appearance)

Name displayed on NMs R8860 (DTR-GUxxx) R8860 (ADTR-GUxxx)

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RSU60E and R8860E

Difference in appearance

RSU60 Vs RSU60E


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RSU60E and R8860E

Difference in NM interfaces

RSU60 Vs RSU60E

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RSU60E and R8860E

Difference in NM interfaces

R8860 Vs R8860E


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Fiber interfaces

Each FS board supports 6 fiber interfaces.

Each RU supports 2 fiber interfaces.

The fiber supports both star-type and link-type networking

For link-type networking, at most 4 RUs can be connected in

cascading mode.

BBU is at most 40 Km away from the RU.

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CPRI interface configuration rules

BBU is configured with commercial-level SFP: 1.25G/1310nm single

mode optical module with transmitting and receiving integrated

RSU is configured with industrial-level SFP: 1.25G/1310nm single mode

optical module with transmitting and receiving integrated

RRU has been configured SFP itself, so it is unnecessary to configure

additional SFP.

Fibers between BBU and RSU need not be configured separately.

Number of fibers to be delivered depends on the quantity of RSUs, and it

will not be configured on ECC.

CPRI of the BS8800 main cabinet uses the electrical interface and high-

speed cables. That of both the main cabinet and the extension cabinet

use the optical interface.

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Contents



Introduction to BBU




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High integration

BBU supports 60 TRXs.

RU supports 6TRX/2TRX.

A fiber can support 24 TRX

Support smooth evolution to LTE and HSPA+

All IP transmission based structure Support multi-band RRU


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Multiple new functions

Baseband frequency hopping

Transmitting and receiving diversity

Combine multiple carriers

Applied for express railways

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Basic concept baseband frequency hopping

Frequency hopping refers to that multiple frequencies are used for radio

transmission of a single speech/signaling/data link. The transmission

frequency keeps stable within the transmission period of a burst pulse. For

different burse pulses of the same link, the transmission frequency may

change. The MS may be affected by the fading effect of some frequency

on the transmission path. GSM coding and inter-leaving technology helpsto minimize the impact of single-burst lost to the voice quality.

Baseband frequency hopping means that multiple transmitters work on

their respective frequencies, and switch signals of different channels to

different transmitters to send them on the baseband, thus to achieve the

function of frequency hopping.

The function of frequency hopping is easy and feasible. Because of limited

number of TRXs, there are a just a few frequencies available for frequency

hopping.

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Baseband frequency hopping technology

For baseband frequency hopping, each RU has a fixed frequency. The

baseband board figures out the frequency of each timeslot over the

TDMA frame according to frame No. (FN), mobile allocation table (MA),

mobile allocation index offset (MAIO), and frequency hopping serial No.

(HSN). Then, the baseband board switches the data to the

corresponding RU according to the frequency, and receives uplink

data from the corresponding RU. The baseband frequency hopping

can be implemented by DSP, or FS or FPGA on the BP board. At

present, a DSP processes one frequency hopping group, which can

have 12 frequencies at most.

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Basic concept MCUM

Multi-carrier unite combine (MCUM) is a product after 3G OTSRis introduced into the GSM system.

To meet complex requirements for coverage and high-speed

moving, antennas are placed at multiple positions and multiple

angles to cover each single cell.

The SDR solves the problem about antenna extension and

repeaters by distributing the RRU remotely.

Downlink signals of multiple RRUs are same. The uplink

perform selective combination, that is, MCUM.

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Coverage map of express railways

Cell

1

Cell

2

Cell

n

BBU

Abis

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Features of the technology

The downlink of multiple carriers are same signals.

TRXs of an RU should be processed on the same UBPG. A

UPBG can process 12 TRXs at most.

Uplink signals are combined selectively, which can improve

sensitivity.

Quantity of configured RUs increases. Quantity of configured UBPGs increases.

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Lower cost

Reduce the cost per unit

Reduce the cost of typical networking

Reduce the operation cost

Reduce the maintenance cost

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Review

Basic concepts of SDR

SDR hardware and software structure

3 types of SDR base stations

Functions of each SDR board

Various interface of SDR

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4.Introduction to GU SDR BTS

Documents

Transcript of 4.Introduction to GU SDR BTS