A PHP Error was encountered
Severity: Warning
Message: fopen(/var/lib/php/sessions/ci_sessionp6piq220aaqiabg09bv7fn190do1p8la): Failed to open stream: No space left on device
Filename: drivers/Session_files_driver.php
Line Number: 177
Backtrace:
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)
Filename: Session/Session.php
Line Number: 137
Backtrace:
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Undefined array key "choices"
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 249
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: 8192
Message: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated
Filename: models/Detail_model.php
Line Number: 71
Backtrace:
File: /var/www/html/application/models/Detail_model.php
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: 8192
Message: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated
Filename: helpers/my_audit_helper.php
Line Number: 8919
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Undefined array key "choices"
Filename: controllers/Detail.php
Line Number: 256
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 256
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 256
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 257
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 257
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 258
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 258
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 259
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 259
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Undefined array key "usage"
Filename: controllers/Detail.php
Line Number: 260
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 260
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Trying to access array offset on value of type null
Filename: controllers/Detail.php
Line Number: 260
Backtrace:
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 143
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
File: /var/www/html/application/helpers/my_audit_helper.php
File: /var/www/html/application/helpers/my_audit_helper.php
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
A PHP Error was encountered
Severity: Warning
Message: Attempt to read property "Count" on bool
Filename: helpers/my_audit_helper.php
Line Number: 3100
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/application/controllers/Detail.php
File: /var/www/html/index.php
Uniformity improvement on received optical power for an indoor visible light communication system with an angle diversity receiver. | LitMetric
In this work, an angle diversity receiver (ADR) structure is proposed to optimize the uniformity of the received optical power distribution in an indoor visible light communication (VLC) system. Taking the rectangular and hybrid layouts with 16 light-emitting diodes as examples, different inclination angles and the number of side detectors are investigated with three diversity combining techniques in a typical room, where the primary reflection of the wall is considered. Simulation results showed that the inclination angles and the number of side detectors would affect the variance and average of the received optical power, and the variance would decrease with the increase of the number of side detectors. In addition, maximal ratio combining is more suitable for the ADR when the variance and average of the received optical power are considered simultaneously. By applying the ADR with five side detectors, the variances of the received optical power will decrease by 81.34% and 86.09% under the rectangle layout and the hybrid layout, respectively. This work will benefit the design and development of the VLC system.
Similar Publications
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
