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TETRA
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TD-SCDMA
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CDMA - Code Division Multiple Access

Overview

Frequency Bands

Frequency Range

Duplex

Band Class 0

824.0 – 849.0 MHz(uplink)
869.0 – 893.0 MHz (downlink)

45 MHz

Band Class 1

1850.0 – 1910.0 MHz (uplink)
1930.0 – 1990.0 MHz (downlink)

80 MHz

Band Class 2

872.0 – 915.0 MHz (uplink)
917.0 – 960.0 MHz (downlink)

45 MHz

Band Class 3

887.0 – 925.0 MHz (uplink)
832.0 – 870.0 MHz (downlink)

45 MHz

Band Class 4

1750.0 – 1780.0 MHz (uplink)
1840.0 – 1870.0 MHz (downlink)

90 MHz

Band Class 5

411.0 – 483.0 MHz (uplink)
421.0 – 494.0 MHz (downlink)

10 MHz

Band Class 6

1920.0 – 1980.0 MHz (uplink)
2110.0 – 2170.0 MHz (downlink)

90 MHz

Channel spacing

30 kHz

Channel Bandwidth

1.2288 MHz

Modulation

QPSK (forward link)
OQPSK, HPSK (reverse link)

Chip Rate

1.2288 Mcps

Access format

CDMA

Speech

Digital transmission with one out of several possible vocoders:
QCELP (8 kbit/s) (quadrature code excited linear prediction)
EVRC (8 kbit/s) (enhanced variable rate codec)
ACELP (13 kbit/s) (algebraic code excited linear prediction)

Power control

Up to 800 power control commands per second changing the level in increments of 1 dB.

Applications

CDMA is a growing mobile device standard, with networks established in a large number of countries around the world.  CDMA supports data connections through circuit switched data (up to 14.4 kbit/s) and packet switched data (up to 307kbit/s, fl). A 3G evolution path for higher data rates utilizing 1xEV-DO (1x Evolution-Data Only) and 1xEV-DV (1x Evolution-Data and Voice) technologies exist and is being deployed.

In addition to voice services, users are experiencing a host of advanced services, including web browsing, m-commerce, MMS (multimedia messaging services), streaming video, games, enterprise solutions and email.

Technology in brief

CDMA is a "spread spectrum" technology, allowing many users to occupy the same time and frequency allocations in a given band/space. As its name implies, CDMA assigns unique codes to each communication to differentiate it from others in the same spectrum. In a world of finite spectrum resources, CDMA enables many more people to share the airwaves at the same time than do alternative technologies.

cdmaOne describes a complete wireless system based on the TIA/EIA IS-95 CDMA standard, including IS-95A and IS-95B revisions. It represents the end-to-end wireless system and all the necessary specifications that govern its operation. cdmaOne provides a family of related services including cellular, PCS and fixed wireless (wireless local loop).

CDMA2000 represents a family of ITU-approved, IMT-2000 (3G) standards and includes CDMA2000 1X and CDMA2000 1xEV technologies. They deliver increased network capacity to meet growing demand for wireless services and high-speed data services. CDMA2000 1X was the world's first 3G technology commercially deployed (October 2000).

Typical measurements

Transmitter Measurements:

  • Maximum Output Power
  • Minimum Output Power
  • Frequency Error
  • Transmit Modulation
  • Waveform Quality (Rho)

Receiver Measurements:

  • Reference Sensitivity Level
  • Maximum Input Level

Willtek Test Instruments


终端测试产品

 
Point-of-sale/Point-of-return tester:
> 4350 Mobile Fault Finder Series


Service tester (low end):
> 4350 Mobile Fault Finder Series


Service tester (mid range):
> 4400 Mobile Phone Tester Series


Service tester (high end):
> 4400 Mobile Phone Tester Series


Manufacturing tester:
> 4400 Mobile Phone Tester Series



空中接口产品

 
> 8100 General Purpose Receiver


> 8300 Griffin Fast Measurement Receiver


> 8501 GSM Air Interface Test Module


> 更多
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手机服务中心可利用德国威尔泰克公司的4400系列手机综测仪完成HSDPA无线设备的测试 > 更多信息
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