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Multimedia Codecs Based on FFT and Usable with the WiFi Repeaters
Multimedia Codecs Based on FFT and Usable with the WiFi Repeaters
We have recently introduced new methods for the compression, the decompression and the transport of media (audio, image and video).
For more information, see at the following addresses:
Compression of Images and Videos
Long Distance Communications
We noted that these methods are usable with OFDM, OFDMA and SC-FDMA.
We also noted that these methods are compatible with WiFi communications and provided some examples of unique uses.
For more information, see at the following addresses:
Multimedia Codecs Based on FFT and usable with OFDM, OFDMA and SC-FDMA
Multimedia Codecs Based on FFT and Compatible with the WiFI Communications
This information is written for investors, developers and decision makers.
This article aims to demonstrate how these methods can be used with WiFi repeaters that support them, using two frequency ranges: a low-frequency range capable of long-distance UNB communications, and a high-frequency range capable of long-distance OFDM communications.
In reception, each WiFi repeater, in the areas it serves, in addition to performing repeater-to-repeater tasks, converts the received data and then transmits this data on standard WiFi frequencies.
In transmission, each WiFi repeater, in the areas it serves, receives the data transmitted on standard WiFi frequencies, converts it, and then transmits it to the other repeaters.
The dual-channel approach is already used with 5G NR, where we talk about control channels (low frequencies, FR1) and data channels (high frequencies, FR2).
For more information on wireless repeaters and 5G NR, see at the following addresses:
Wireless Repeater
5G NR
With 5G NR, the frequency ranges are as follows:
- FR1: 410 to 7125 MHz.
- FR2-1: 24250 to 52600 MHz.
- FR2-2: 52600 to 71000 MHz.
- FR2-NTN: 17300 MHz to 30000 MHz (NTN for Non Terrestrial Networks).
Our methods target the following frequency ranges:
- High frequencies: 24 GHz, 61 GHz, 122 GHz, 244 GHz.
- Low frequencies: 433 MHz, 868 MHz, 902 MHz.
- Very low frequencies are possible, with the necessary authorizations: 6.765 MHz, 26.957 MHz, 40.66 MHz.
The normal WiFi frequencies affected are: 2.4 GHz, 5 GHz and 6 GHz.
The high-frequency ranges carry large amounts of data. The error correction is normally used before the OFDM modulations.
The most common error correction methods are: Reed Solomon, Turbo Codes, LDPC (Low-Density Parity-Check), and a variant of LDPC called QC-LDPC (QC for Quasi-Cyclic).
The low-frequency ranges carry control data as well as additional error correction data.
The commonly used additional error correction methods include the Polar Codes, the BCH Codes and the Reed Solomon Codes.
With the media (audio, image, and video), where the sign of the background phases is retained and the phases are set to zero, we recommend the following approach:
In the high-frequency ranges, we use long-distance OFDM methods (foreground in the background phases).
In the low-frequency ranges, we use long-distance UNB methods.
For each frame, the foreground is transformed into two UNB frames.
One or more copies are transported in the background phases, in the high-frequency ranges.
One or more copies can be transported directly in the low-frequency ranges.
No error correction is applied before the OFDM modulations.
The error corrections, such as QC-LDPC, are applied to the amplitudes of the background points.
These error corrections can be partially applied.
The LDPC codes are constructed using a sparse bipartite graph (many zeros).
The QC-LDPC codes are a specific type of LDPC code whose parity check matrix (H) has a particular structure. Instead of being an arbitrary sparse matrix, it is constructed from smaller square blocks, each of which is either a zero matrix or a circulant permutation matrix (CPM).
For more information on LDPC and QC-LDPC codes, see at the following addresses:
Low-density Parity-Check Codes
LDPC / QC-LDPC
We recommend using QC-LDPC codes for error correction applied to the amplitudes of the background points. The parity-check matrix data is easily compressible with long-distance UNB methods and can be dynamically transported in low-frequency ranges.
We use the RLE method to generate two UNB frames from a single frame, and transmit independent UNB frames.
Grouping UNB frames is possible to create OFDM frames. In this case, we assign a global phase sign to each UNB frame and manipulate these signs to achieve a very low PAPR.
Normal error-correction methods are used to secure data in low-frequency ranges. Global LDPC codes suitable for small frames can also be used.
If the data from a copy of the foreground is correctly recovered in the low-frequency or high-frequency ranges, it can be used as additional error correction data in the regions carrying the other copies of the foreground.
Applying error correction to the amplitudes results in the addition of additional data, which must also be included in the background phases.
Note that other pure data can be transported in the background phases, in addition to the data mentioned above.
Note that after placing the foreground and pure data in the background phases, if we return to the amplitudes and apply error corrections, the successful reception of these amplitudes implies the successful reception of the phases, and therefore the successful reception of the foreground and pure data.
Also note that for cameras (IP cameras, smartphone cameras, drone cameras, IoT cameras, etc.), the same or similar algorithms are used for data compression and transmission.
Finally, note that the methods in this article can be used in the general case: first, remove the foreground and then create two frames with the sine and cosine amplitudes. Each of these frames can then be considered as a FFT frame without phase.
We have recently introduced new methods for the compression, the decompression and the transport of media (audio, image and video).
For more information, see at the following addresses:
Compression of Images and Videos
Long Distance Communications
We noted that these methods are usable with OFDM, OFDMA and SC-FDMA.
We also noted that these methods are compatible with WiFi communications and provided some examples of unique uses.
For more information, see at the following addresses:
Multimedia Codecs Based on FFT and usable with OFDM, OFDMA and SC-FDMA
Multimedia Codecs Based on FFT and Compatible with the WiFI Communications
This information is written for investors, developers and decision makers.
This article aims to demonstrate how these methods can be used with WiFi repeaters that support them, using two frequency ranges: a low-frequency range capable of long-distance UNB communications, and a high-frequency range capable of long-distance OFDM communications.
In reception, each WiFi repeater, in the areas it serves, in addition to performing repeater-to-repeater tasks, converts the received data and then transmits this data on standard WiFi frequencies.
In transmission, each WiFi repeater, in the areas it serves, receives the data transmitted on standard WiFi frequencies, converts it, and then transmits it to the other repeaters.
The dual-channel approach is already used with 5G NR, where we talk about control channels (low frequencies, FR1) and data channels (high frequencies, FR2).
For more information on wireless repeaters and 5G NR, see at the following addresses:
Wireless Repeater
5G NR
With 5G NR, the frequency ranges are as follows:
- FR1: 410 to 7125 MHz.
- FR2-1: 24250 to 52600 MHz.
- FR2-2: 52600 to 71000 MHz.
- FR2-NTN: 17300 MHz to 30000 MHz (NTN for Non Terrestrial Networks).
Our methods target the following frequency ranges:
- High frequencies: 24 GHz, 61 GHz, 122 GHz, 244 GHz.
- Low frequencies: 433 MHz, 868 MHz, 902 MHz.
- Very low frequencies are possible, with the necessary authorizations: 6.765 MHz, 26.957 MHz, 40.66 MHz.
The normal WiFi frequencies affected are: 2.4 GHz, 5 GHz and 6 GHz.
The high-frequency ranges carry large amounts of data. The error correction is normally used before the OFDM modulations.
The most common error correction methods are: Reed Solomon, Turbo Codes, LDPC (Low-Density Parity-Check), and a variant of LDPC called QC-LDPC (QC for Quasi-Cyclic).
The low-frequency ranges carry control data as well as additional error correction data.
The commonly used additional error correction methods include the Polar Codes, the BCH Codes and the Reed Solomon Codes.
With the media (audio, image, and video), where the sign of the background phases is retained and the phases are set to zero, we recommend the following approach:
In the high-frequency ranges, we use long-distance OFDM methods (foreground in the background phases).
In the low-frequency ranges, we use long-distance UNB methods.
For each frame, the foreground is transformed into two UNB frames.
One or more copies are transported in the background phases, in the high-frequency ranges.
One or more copies can be transported directly in the low-frequency ranges.
No error correction is applied before the OFDM modulations.
The error corrections, such as QC-LDPC, are applied to the amplitudes of the background points.
These error corrections can be partially applied.
The LDPC codes are constructed using a sparse bipartite graph (many zeros).
The QC-LDPC codes are a specific type of LDPC code whose parity check matrix (H) has a particular structure. Instead of being an arbitrary sparse matrix, it is constructed from smaller square blocks, each of which is either a zero matrix or a circulant permutation matrix (CPM).
For more information on LDPC and QC-LDPC codes, see at the following addresses:
Low-density Parity-Check Codes
LDPC / QC-LDPC
We recommend using QC-LDPC codes for error correction applied to the amplitudes of the background points. The parity-check matrix data is easily compressible with long-distance UNB methods and can be dynamically transported in low-frequency ranges.
We use the RLE method to generate two UNB frames from a single frame, and transmit independent UNB frames.
Grouping UNB frames is possible to create OFDM frames. In this case, we assign a global phase sign to each UNB frame and manipulate these signs to achieve a very low PAPR.
Normal error-correction methods are used to secure data in low-frequency ranges. Global LDPC codes suitable for small frames can also be used.
If the data from a copy of the foreground is correctly recovered in the low-frequency or high-frequency ranges, it can be used as additional error correction data in the regions carrying the other copies of the foreground.
Applying error correction to the amplitudes results in the addition of additional data, which must also be included in the background phases.
Note that other pure data can be transported in the background phases, in addition to the data mentioned above.
Note that after placing the foreground and pure data in the background phases, if we return to the amplitudes and apply error corrections, the successful reception of these amplitudes implies the successful reception of the phases, and therefore the successful reception of the foreground and pure data.
Also note that for cameras (IP cameras, smartphone cameras, drone cameras, IoT cameras, etc.), the same or similar algorithms are used for data compression and transmission.
Finally, note that the methods in this article can be used in the general case: first, remove the foreground and then create two frames with the sine and cosine amplitudes. Each of these frames can then be considered as a FFT frame without phase.
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