Referred to as the third generation (3G) cellular communication system, UMTS promises to provide high speed data access at up to 2 Mbps. Nuntius has solutions for UMTS phone developers in Layer 1 and Layer 2 functions of both FDD and TDD modes. Below is a list of some of the characteristics of UMTS. For more information contact Nuntius Systems, Inc.

Duplex - FDD/TDD

Transmitter power:     -    30 dbm (max)

Data rate:

8 kbps to 2 Mbps

Channel codes

Convolutional inner code (1/2 or 1/3)
Optional outer Reed-Solomon code (4/5)
Service specific coding such as Turbo code
Unequal repetition and / or puncturing for rate matching

Interleaving

Inner: Block interleaving with variable block size (10 - 150 ms)
Outer: Block interleaving with variable block size (10 - 150 ms)

Channelization codes

Orthogonal Variable Spreading Factor code (OVSF)

 

Scrambling codes (reverse link)

Primary code         -     256 chip Kasami code
Secondary code    -     Segment of long Gold code

Scrambling codes (forward link)

Segment of long Gold code
Short Orthogonal codes on Physical and Synchronization channels

Modulation (forward link)

Data             -     QPSK

Spreading    -     QPSK

Channels

Common Pilot channel

       Primary common control Physical channel (P-CCPCH)

             Synchronization channel (SCH)

       Secondary common control Physical channel (S-CCPCH)

Paging information

       Physical downlink shared channel (PDSCH)

       Page indication channel (PICH)

       Acquisition indication channel (AICH)

       Dedicated Physical Data Channel (DPDCH)

       Dedicated Physical Control Channel (DPCCH)

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The following is a list of the standard library functions to perform the various aspects of UMTS. Although these functions can be implemented in a DSP or the ARM RISC architecture, due to the high chip rates, it may be necessary to implement some functions in an FPGA or ASIC. However, there are some high MIPS and low power chips coming out into the market that may allow all the layer 1 functions to be implemented in software. The advantage to this is the possibility of mulitprotocol stacks that include layer 1 tasks allowing a mobile to operate in multiple modes with simpler hardware designs.

Speech codec

Adaptive Multirate (AMR) voice codec     -     4.75 to 14 kbps

Channel codes

Forward Error Correction (FEC) coder
Cyclic Redundancy Check (CRC) coder
Convolutional inner coder (rate 1/2 or 1/3 with K=9)
Reed-Solomon outer coder
Service specific Turbo coder
Unequal repetition coder
Puncturing coder

Interleaver

Inner block interleaving
Outer block interleaving

PN codes

Orthogonal Variable Spreading Factor (4 to 256) generator
Short code generator (complex code from two 256 chip Kasami codes)
Long code generator (segment of Gold code)

Channel models

Multipath propogation (1-ray, 2-ray, 3-ray)

Modulation / Demodulation

QPSK
BPSK
RAKE Receiver

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