外文文献翻译--数据包处理的硬件支持

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1、 中文 4130 字 （ 二 一 四 年 六 月本科毕业设计外文文献翻译 题 目： P a c k e t H a n d l i n g H a r d w a r e S u p p o r t 学生姓名 ： 学 院 ： 系 别： 专 业： 班 级： 指导教师 ： 1 Packet Handling Hardware Support 参考文献： Texas Instruments.CC1101 Low-Power Sub-1 GHz RF Transceiver.www. . 2013 The CC1101 has built-in hardware support for packet

2、oriented radio protocols. In transmit mode, the packet handler can be configured to add the following elements to the packet stored in the TX FIFO: A programmable number of preamble bytes A two byte synchronization (sync) word. Can be duplicated to give a 4-byte sync word (recommended). It is not po

3、ssible to only insert preamble or only insert a sync word A CRC checksum computed over the data field. The recommended setting is 4-byte preamble and 4-byte sync word, except for 500 kBaud data rate where the recommended preamble length is 8 bytes. In addition, the following can be implemented on th

4、e data field and the optional 2-byte CRC checksum: Whitening of the data with a PN9 sequence Forward Error Correction (FEC) by the use of interleaving and coding of the data (convolutional coding) In receive mode, the packet handling support will de-construct the data packet by implementing the foll

5、owing (if enabled): Preamble detection Sync word detection CRC computation and CRC check One byte address check Packet length check (length byte checked against a programmable maximum length) De-whitening De-interleaving and decoding Optionally, two status bytes (see Table 27 and Table 28) with RSSI

6、 value, Link Quality Indication, and CRC status can be appended in the RX FIFO. 2 Table 27: Received Packet Status Byte 1(first byte appended after the data) Bit Field Name Description 7:0 RSSI RSSI value Table 28: Received Packet Status Byte 2(second byte appended after the data) Bit Field Name Des

7、cription 7 CRC_OK 1:CRC for received data OK (or CRC disabled) 0:CRC error in received data 6:0 LQI Indicating the link quality Note: Register fields that control the packet handling features should only be altered when CC1101 is in the IDLE state. 1. Data whitening From a radio perspective, the ide

8、al over the air data are random and DC free. This results in the smoothest power distribution over the occupied bandwidth. This also gives the regulation loops in the receiver uniform operation conditions (on data dependencies). Real data often contain long sequences of zeros and ones. In these case

9、s, performance can be improved by whitening the data before transmitting, and de-whitening the data in the receiver. With CC1101, this can be done automatically. By setting PKTCTRLO. WHITE_DATA=1, all data, except the preamble and the sync word will be XOR-ed with a 9-bit pseudo-random (PN9) sequence before being transmitted. This is shown in Figure 16. At the receiver end, the data are XOR-ed with the same pseudorandom sequence. In this way, the whitening is reversed, and the original data appear in the receiver. The PN9sequence is initialized to all 1s.