From SDR to DWCS

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From SDR to DWCS

• Prof. WANG, Jing
• wangj_at_tsinghua.edu.cn
• Tsinghua National Lab.
• for Information Science and Technology
• Tsinghua University, Beijing 100084, China

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Highlight

• Basic Concepts of SDR
• PC Based SDR
• Applications---DWCS
• Conclusions

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Basic Concepts SDR Definition

• Digitalization closed to RF
• Common Hardware Platform
• Programmable and reusable hardware
• Reconfigurable hardware and software
  constructions
• Opening construction for hardware and software

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Basic Conception-Initial SDR

• Digital Radio

Channel Coding

Voice Codec Video Codec



Antenna Array





CV-Codec
QPSK





RF TRx



M-QAM

Turbo



OFDM


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Basic Conception-Common Platform
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Key Technologies

• Hardware
• Programmable broadband RF front-end
• High speed, high accuracy AD/DA converters
• High speed and high efficient DSP
• High speed and open BUS
• Software
• Core construction
• Management of hardware and software
• Kernel software modules

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PC Based SDR-1
MCU
A/D
D/A
IAU
IAU
IAU
LAN/Ethernet
IAU
IAU
DUC
DDC
IAU
IAU
IAU
CODEC
RRC
DSPs
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PC Based SDR-4

• System layers

MMI
APP_L
Application Program
API
System Control Interface
ADP_L
OS




High Data Rate Network
RF Front end
PHY_L
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PC Based SDR-5

• MM Interface

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PC Based SDR-6

• Common platform
• PC, Ethernet, Switching, and FPGA
• Common software environment
• Linux?C
• Developed Cooperative protocol
• RTCPP-Real Time Cooperative Processing Protocol

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PC Based SDR-Hardware1
DDC/DUC??A/D/A??
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PC Based SDR-Hardware2
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PC Based SDR-Software

• RTCPP-Real Time Cooperative Processing Protocol
• Description based function calling system
• Function Call
• The operation instruction sets are located in the
  PCs. one operation is corresponded to one
  function, the pointer and processed data are
  transmitted through the network.

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Applications

• Reconfigurable and downloadable radio equipment
  is the SDRs future
• International standards for the hardware,
  software, and their interface
• Reconfigurable handset
• Multi-radio Base station productions

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Distributed Wireless Communication System -DWCS
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Conventional Architecture of Mobile Systems
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Architecture of DWCS
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DWCS
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Software radio/Network radio
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Simulation results

• UPLINK CAPACITY
• 1 transmitting antenna
• DOWNLINK CAPACITY
• 1 receiving antenna
• Capacity definition
• User number per antenna
• Voice channels in a WCDMA system is assumed

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Effect of path loss exponent ? on capacity
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Forward Capacity of Equal Gain Transmission and
Maximum Ratio Transmission
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Conclusions

• SDR is a kind of technology to realize radio
  systems
• SDR is a way to produce low cost, high
  performance, and personalized radio system
• DWCS is an extension of SDR

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Conclusions-DWCS

• No fast handoff problem
• Large capacity
• Much lower power consumption
• Seamless coverage
• Suitable for non-uniformly distributed traffic
• Opened structure
• Flexible
• Extendibility
• Scalability
• Easy to update