Compare 2D ACO-OFDM vs 2D DCO-OFDM

This post discovers the difference between 2D ACO-OFDM and 2D DCO-OFDM from implementation perspective. The Simulation Package allows us to test all the performance without any hardware configuration needed. Besides the simulation package (package 1), optical link package (package 2) and optimal optical link package (package 3) are within the 2D-OFDM Code packages. 2D Mapping …

NEW 2D-OFDM Codes available

We now release new 2D-OFDM Codes (2D ACO-OFDM) and update existing Code adding many interesting features. Notably, TWO MORE new software packages are now included. NEW Package 1 (ACO/DCO-OFDM Simulation) New features This allows for choosing different modulation modes, including Modulation option: 2D ACO-OFDM or 2D DCO-OFDMChangeable clipping factor for reducing PAPREnable Inner-FEC and spatial-pilots …

C-OOK Code Update available

We now release new updates of the C-OOK Codes by adding several interesting features as follows. (Two additional software Packages, but the same single price.) Package 1 (Back to Back Link) New features This allows for choosing different modulation modes for Tx, configuring (simulated) cameras and channel. All are live demonstration, which are similar real …

A-QL Code Update available

We now release an update of the A-QL Code by adding several interesting features: Switching between 16*16 and 32*32 cells modesAuto-threshold feature for RXEnable button for option of RGB colors calibrationFeedback nodes for a clean block diagram Please download the following PPT file for a review of the software User Interface (TX and RX). A-QL …

Implementation of HA-QL Code

HA-QL (Hidden Asynchronous Quick-Link) is a hidden modulation mode among Screen-2-Camera operating modes within the IEEE 802.15.7-2018 Optical Wireless Communication standard. An interesting feature of HA-QL is that it allows for controlling the peak-to-peak amplitude of the intensity modulation, from a visible code to a hidden code. The HA-QL Code Project is cleaned, well-packed and documented. Technical …

(PPT) BER measurement of A-QL

A-QL stands for Asynchronous Quick Link, a two-dimensional multi-band color code sequential transmission protocol from a screen to camera. The A-QL is one of mode within the IEEE 802.15.7-2018 Optical Wireless Communication standard. For your convenience, we have measured the BER performance of A-QL code. The results showed that A-QL can support the transmission distance of 4.5m with the wide …

(PPT) Presentation of technical features: A-QL vs 2D-OFDM

The following PPT file presents the technical features of A-QL code versus 2D-OFDM code. Also, we have included the performance comparison between the codes. Please download the file for more technical details. Presentation of technical features in 2D-OFDM and A-QL (PPT file)Download Notice: A-QL stands for Asynchronous Quick Link, a two-dimensional multi-band color code sequential transmission protocol from …

(PPT) – BER measurement: 2D-OFDM vs A-QL

A-QL stands for Asynchronous Quick Link, a two-dimensional multi-band color code sequential transmission protocol from a screen to camera. The A-QL is one of mode within the IEEE 802.15.7-2018 Optical Wireless Communication standard. After the IEEE 802.15.7-2018 A-QL color code for Optical Camera Communication, 2D-OFDM is one of the next generation for Mbps data rate transmission from a screen TX to a camera. …

FREE Software to measure the sampling rate of rolling shutter cameras!

I remember that some of my colleagues had really tough time figuring out what is the sampling rate of a rolling shutter camera since camera producers never ever shown the value! We are not talking about the frame rate of camera if you are missing understanding. The reason was quite understandable, because the sampling rate …

2D-OFDM for Optical Camera Communication

OFDM is well-known for LiFi; however, it is still fresh advanced waveform for OCC. This post shares an implementation of 2D-OFDM for Screen-to-Camera communication system in which a massive number of display cells brings a great advantage for communication. A full journal version of this topic is available online at IEEE Access here. System Architecture …

Needs for OCC: Line code, Scrambler, Interleaving, and CRC

This post discusses several aspects of light communication as follows Line Coding: What and Why Line Coding is needed? Other choices? Scrambler: What is a Scrambler? OCC needs this? Interleaving: Purpose and Generation. Cyclic Redundancy Check: Where it is applied.   Run-length limited code for Visible Light Communication According to Wikipedia, for reliable clock recovery …

Customizing MAC for OCC Modes

This post discusses the topic related to OCC MAC and MPDU.   IEEE 802.15.7m OCC MAC Layer "Use of over-the-air MAC frame configuration is forbidden for PHY types IV, V and VI. It is mandatory MAC frame configuration be done via the MAC PIB. This is due to the fact that unlike traditional wireless LAN/PAN, the data …

Software-defined Configuration method for OCC Systems

The purpose of the post is to specify the PIB attributes for configuring a particular OCC PHY mode. Any OCC PHY mode is co-existing with the others and recognizable by a specific receiver once the PIBs are specified. The configuration of PHY-PIB attributes is software-defined (App-based). Without using PHY-frame overhead, the App-based configuration is communication …

HS-PSK: High-rate transfer over RoI(s)

HS-PSK is an operating mode being standardized at IEEE 802.15.7m. This post describes what it is for and how it operates. Figure 1 illustrates an example in which an Rx can select the link properly for an intended usage. The link setup procedure is solved by the RoI-Signaling waveform, while this high-rate waveform is additionally …

S2-PSK: A choice for RoI-Signaling

S2-PSK is an operating mode being standardized at IEEE 802.15.7m. This post describes what it is for and how it operates.   Technical Considerations for a RoI-signaling Waveform Even though RoI-signaling mode has a very low data rate, it is indispensable to the OCC system operating in a challenging condition such as V2X. The general …

PPDU: PHY frame format for CM-FSK & C-OOK

This post reviews the design of the Physical-layer Packet Data Unit (PPDU) for CM-FSK  and C-OOK operating modes within PHY V of IEEE 802.15.7m. For a detailed explanation of how these modes operate, please visit the previous CM-FSM post and the previous C-OOK post. The comparison between these modulation schemes for rolling shutter OCC was discussed …

PPDU: PHY frame format for Screen Modulation Systems (A-QL & HA-QL)

This post reviews the design of the Physical-layer Packet Data Unit (PPDU) for A-QL and HA-QL operating modes within PHY IV Screen modulation of IEEE 802.15.7m. For implementation, the Data Frame Format is crucial; each operating mode has its packet format and the format specification has its reason. At least, time is spent on optimizing …

HA-QL: Part 2 – Hiding data into Screen using Wavelet Transform

HA-QL (Hidden Asynchronous Quick-Link) is a hidden modulation mode among Screen-2-Camera operating modes those are being standardized at IEEE 802.15.7m. The previous post explains the principle to generate a hidden code on the screen using an additional intensity modulator after the bit-intensity mapper. However, the modulation of screen intensity dramatically degrades the communication performance. In …

HA-QL: Part 1- Intensity modulation for Hidden Screen Code

HA-QL (Hidden Asynchronous Quick-Link) is a hidden modulation mode among Screen-2-Camera operating modes those are being standardized at IEEE 802.15.7m. This post describes what it is for and how it operates. Introduction The name Hidden A-QL briefly describes how it operates. The mapping from bits into the screen cells during modulation in HA-QL shall follow …

A-QL: Part 2 -BER Measurement

A-QL (Asynchronous Quick-Link) is a Screen-2-Camera operating mode being standardized at the IEEE 802.15.7m. This post introduces the BER measurement method and the performance of A-QL system. See this video demo for the BER measurement scenario: https://www.youtube.com/watch?v=Mkq2lYKzQsQ   Experimental Setup The scenario for measuring BER is illustrated in Figure 1. The bit rate is measured …

A-QL: Part 1- Introduction of Reliable Screen-Camera Communication

A-QL (Asynchronous Quick-Link) is a Screen-2-Camera operating mode being standardized at IEEE 802.15.7m. This post describes what it is for and how it operates. Figure 1 - Example of color code displaying with video on a screen And before we start talking about A-QL system, a short demo of it is here: https://www.youtube.com/watch?v=B6uBTSdh44Y Introduction The …

Rolling shutter OCC: Communication distance vs Data rate Trade-off

The classification of OCC technologies has been given. Being a part of non-flicker modulation series, with the vast usage of rolling shutter cameras in the camera market, the use of rolling shutter cameras in OCC systems takes advantage of the high sampling rate of the rolling shutter mechanism, which sequentially exposes pixel lines to the …

C-OOK: Customizing OOK for Optical Camera Communication

C-OOK stands for Camera ON-OFF Keying, is also an operating mode being standardized in IEEE 802.15.7m. This post reviews the operation of this mode and highlights its characteristics. See video demo 1 (Manchester coded for Rolling shutter OCC): https://www.youtube.com/watch?v=tMaR7B5M3QI See video demo 2 (4B6B coded for Rolling shutter OCC): https://www.youtube.com/watch?v=wPbeZZxEMVY C-OOK for OCC and its …

CM-FSK: Customizing FSK for Optical Camera Communication

CM-FSK stands for Camera M-ary Frequency Shift Keying, is also an operating mode being standardized in IEEE 802.15.7m. This post reviews the operation of this mode and highlights its characteristics. See video demo 1 to have a brief understanding of CM-FSK System: (7m transmission) https://www.youtube.com/watch?v=cUt5zbRSyoQ Also, video demo 2 (35m transmission distance): https://www.youtube.com/watch?v=BVqh570bCRY&t=5s   FSK …

What is Optical Region-of-Interest Signaling?

In the context of a safety assistance communication-based solution, OWC is a strong candidate for delivering the V2V communication power to cars. It is realized that the LED lighting is quipped to car mandatorily, meanwhile, a camera is considered as one of the indispensable sensors for car vision. The existence of supportive infrastructure enables the …

A comparison between OCC standardization groups within IEEE 802.15

This post briefly reviews the current status of standardization groups within IEEE 802.15 There are IEEE standards covering the optical spectrum, IEEE 802.15.7-2011 std., known as VLCIEEE 802.15.7m std., (publication in 2018, as expected), including OCC modesIEEE 802.15.13 std., (ongoing), adding LiFi (IEEE 802.15.7-2011 std. is also the base document as IEEE 802.15.7m)IEEE 802.11, introducing LiFi to 802.11IEEE 802.15 …

PHY modes within IEEE 802.15.7m draft – a quick review

PHY operating modes  The latest IEEE 802.15.7m draft standard (until Aug. 2018) is on the Sponsor Balloting recirculation. This version has updated a lot in compared to the previous version before LiFi modes are moved to new task group under IEEE 802.15. A list of operating modes between two drafts is a good start. Notation …