Welcome new members

We are welcoming three key members to our group. They are: A firmware engineer (Device API)A software coderA system-level architecture We plan to bring more excellent demonstrations to you soon in the next implementation phase. Wish every one have success and happiness! The OpticalPress Team

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 …

Update OpenSource List

The OpticalPress Team is happy to provide Open Source Codes based on IEEE 802.15.7-2018 Optical Wireless Communication (OWC) standard, the most recent international standard that includes Optical Camera Communication (OCC) technologies. We believe that the codes are beneficial for the implementation of your novel ideas as well as practical comparison purposes. We were lucky and …

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. …

(PPT) – Generation of 2D-OFDM

Our 2D-OFDM implementation is mature by the employment of MIMO sub-transmitters within a single TX, each sub-transmitter is an independent 2D-multi-carrier modulator. For your convenience, the generation of 2D-OFDM is summarized in the following PPT file. Please download the file for your reference. Generation of 2D-OFDM (PPT file)Download

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 …

Performance of Screen OCC: 2D-OFDM vs. A-QL

In the previous posts, the implementation demo and the implementation guidance of the Screen-OFDM system were shown. The measured performance comparison between Screen-OFDM and a traditional A-QL in IEEE 802.15.7m is reported in this post. Overview of 2D-OFDM vs A-QL A-QL is the single-carrier modulation while 2D-OFDM is the multi-carrier modulation approach applied for the …

Generation of Screen-OFDM

In the previous post, an implementation demo of the Screen-OFDM system was shown. The detailed generation of Screen-OFDM (2-dimensional OFDM) is described in this post. Index Terms: Optical Camera Communication, OCC, OFDM, optical OFDM, 1D-OFDM, 2D-OFDM,  OFDM-OCC, Screen OFDM. Benefit of OFDM 1) General Benefits The concept of OFDM has reached sufficient maturity for standardization and employment …

Neural Network for Optical Wireless Communication

This implementation of Neural Network (NN) programmed in Python + Labview shows the feasibility of Artificial Intelligence (AI) assisted Decoder, particularly in our OWC system. In this post, some idea of NN is disclosed, and some piece of implementation results are provided for explanation. In general, NN is very helpful for our OWC if it …

My LiFi demo for ECG transmission

This is a small implementation prepared for our proposal in applying light communication to e-Health. I prepared this demo within a very short time (nearly three weeks) just to test the feasibility of LiFi in transmitting biomedical signal (i.e., ECG). Our demo illustrated that the requirement of communication bandwidth for transmitting the ECG signal can be …

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 …

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 …

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 …

FEC: Generation of Reed-Solomon and Convolutional Code

Reed Solomon and Convolutional Code are chosen for IEEE 802.15.7-2011 and IEEE 802.15.7m implementation. In this post, we will review the generation of the codes and simulate their performance for comparison. Reed Solomon  Systematic RS codes are used for FEC (typically outer FEC) with GF(16), generated by the polynomial x4+x+1. The generators for the RS(n, …

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 …

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 …

Classification of OCC Technologies

Table 1- Classification of OCC, its expected performance, and intended usages Given that various modulation schemes for OCC systems have been investigated till the date, the proper modulation scheme should depend on both Tx and Rx. Table 1 suggests to classify OCC schemes into four categories under the following considerations: (i) The method by which …