CC2480
T C
I-phase
Q-phase
1
1
0
1
1
0
0
1
1
1
0
0
0
0
1
1
0
1
0
1
0
0
1
0
0
0
1
0
1
1
1
0
2T C
Figure 11: I / Q Phases when transmitting a zero-symbol chip sequence, T C = 0.5 μs
10.2 Demodulator, Symbol Synchronizer and Data Decision
The block diagram for the CC2480 demodulator
is shown in Figure 12. Channel filtering and
frequency offset compensation is performed
digitally. The signal level in the channel is
estimated to generate the RSSI level. Data
filtering is also included for enhanced
performance.
Soft decision is used at the chip level, i.e. the
demodulator does not make a decision for
each chip, only for each received symbol. De-
spreading is performed using over-sampling
symbol correlators. Symbol synchronization is
achieved by a continuous start of frame
delimiter (SFD) search.
With the ±40 ppm frequency
accuracy
The CC2480 demodulator also handles symbol
requirement from [1], a compliant receiver
must be able to compensate for up to 80 ppm
or 200 kHz. The CC2480 demodulator tolerates
up to 300 kHz offset without significant
degradation of the receiver performance.
rate errors in excess of 120 ppm without
performance degradation. Resynchronization
is performed continuously to adjust for error in
the incoming symbol rate.
I / Q Analog
IF signal
ADC
Digital
IF Channel
Filtering
Frequency
Offset
Compensation
Digital
Data
Filtering
Symbol
Correlators and
Synchronisation
Data
Symbol
Output
Average
RSSI
Generator
RSSI
Correlation
Value (may be
used for LQI)
Figure 12: Demodulator Simplified Block Diagram
10.3 Frame Format
CC2480 has hardware support for parts of the
IEEE 802.15.4 frame format. This section
gives a brief summary to the IEEE 802.15.4
frame format, and describes how CC2480 is
set up to comply with this.
Figure 13 [1] shows a schematic view of the
IEEE 802.15.4 frame format. Similar figures
describing specific frame formats (data
frames, beacon frames, acknowledgment
frames and MAC command frames) are
included in [1].
CC2480 Data Sheet SWRS074
Page 31 of 43
相关PDF资料
CDJB3 JUNCTION BOX COLORDRV 1/IN 3/OUT
CEA-06-062UR-350 STRAIN GAGE 350 OHM RECT
CEA-06-062UT-350 STRAIN GAGE 350 OHM TEE
CEA-06-062UW-350 STRAIN GAGE 350 OHM LINEAR
CEA-06-062WT-350 STRAIN GAGE 350 OHM TEE
CEA-06-125UN-350 STRAIN GAGE 350 OHM LINEAR
CEA-06-125UR-350 STRAIN GAGE 350 OHM RECT
CEA-06-125UT-350 STRAIN GAGE 350 OHM TEE
相关代理商/技术参数
CC2480A1RTCR 功能描述:射频微控制器 - MCU Z-Accel 2.4 GHz Zig Bee Processor RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:Si100x 数据总线宽度:8 bit 最大时钟频率:24 MHz 程序存储器大小:64 KB 数据 RAM 大小:4 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:LGA-42 安装风格:SMD/SMT 封装:Tube
CC2498-000 功能描述:集管和线壳 MTCPQKT1R2SFDD RoHS:否 产品种类:1.0MM Rectangular Connectors 产品类型:Headers - Pin Strip 系列:DF50 触点类型:Pin (Male) 节距:1 mm 位置/触点数量:16 排数:1 安装风格:SMD/SMT 安装角:Right 端接类型:Solder 外壳材料:Liquid Crystal Polymer (LCP) 触点材料:Brass 触点电镀:Gold 制造商:Hirose Connector
CC24BODKCV3SRD302Q250M 制造商:Ferraz Shawmut 功能描述:
CC24BODKCV3SRE300Q100M 制造商:Ferraz Shawmut 功能描述:
CC24BODKCV3SRE300Q20M 制造商:Ferraz Shawmut 功能描述:
CC24BODKCV3SRE300Q63M 制造商:Ferraz Shawmut 功能描述:
CC24BODKCV3SRF302Q400M 制造商:Ferraz Shawmut 功能描述:
CC-24K2-CP 功能描述:MODEM 2400BAUD PARALLEL 3.3V RoHS:否 类别:集成电路 (IC) >> 接口 - 调制解调器 - IC 和模块 系列:- 标准包装:25 系列:- 数据格式:V.21,V.22,V.23,V.29,V.32,V.34,V.90,V.92,Bell 103,Bell 212A 波特率:33.6k 电源电压:3.3V 安装类型:- 封装/外壳:- 供应商设备封装:- 包装:托盘 配用:591-1013-ND - KIT DEV SOCKETMODEM PARALLEL591-1009-ND - KIT DEV SRL SOCKETMODEM UNIVERSL 其它名称:MT5656SMI-P-V-34.R2-SPMT5656SMI-P-V-34.R2-SP-NDQ4711574