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Merge branch 'docs/update_wifi_csi_sub_carrier_index_doc_v4.2' into 'release/v4.2'

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docs:update wifi sci subcarrier index docs (v4.2)

See merge request espressif/esp-idf!18943
This commit is contained in:
Jiang Jiang Jian
2022-07-10 15:40:14 +08:00
parent 5f5a2d9c5a 496b27eb0a
commit f735dfa617
2 changed files with 13 additions and 1 deletions
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12
docs/en/api-guides/wifi.rst
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@ -1732,6 +1732,18 @@ All of the information in the table can be found in the structure wifi_csi_info_
- If first_word_invalid field of wifi_csi_info_t is true, it means that the first four bytes of CSI data is invalid due to a hardware limitation in {IDF_TARGET_NAME}.
- More information like RSSI, noise floor of RF, receiving time and antenna is in the rx_ctrl field.
When imaginary part and real part data of sub-carrier are used, please refer to the table below.
+----------------+-------------------+------------------------------+-------------------------+
| PHY standard | Sub-carrier range | Pilot sub-carrier | Sub-carrier(total/data) |
+================+===================+==============================+=========================+
| 802.11a/g | -26 to +26 | -21, -7, +7, +21 | 52 total, 48 usable |
+----------------+-------------------+------------------------------+-------------------------+
| 802.11n, 20MHz | -28 to +28 | -21, -7, +7, +21 | 56 total, 52 usable |
+----------------+-------------------+------------------------------+-------------------------+
| 802.11n, 40MHz | -57 to +57 | -53, -25, -11, +11, +25, +53 | 114 total, 108 usable |
+----------------+-------------------+------------------------------+-------------------------+
.. note::
- For STBC packet, CSI is provided for every space-time stream without CSD (cyclic shift delay). As each cyclic shift on the additional chains shall be -200ns, only the CSD angle of first space-time stream is recorded in sub-carrier 0 of HT-LTF and STBC-HT-LTF for there is no channel frequency response in sub-carrier 0. CSD[10:0] is 11 bits, ranging from -pi to pi.

2
docs/zh_CN/api-guides/wifi.rst
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@ -1 +1 @@
.. include:: ../../en/api-guides/wifi.rst
.. include:: ../../en/api-guides/wifi.rst