How does complementary code keying work?

How does complementary code keying work?

In complementary codes, the number of pairs of identical elements, called like elements, in one sequence is equal to the number of pairs of unlike elements in the other sequence having same separation. CCK has a shorter chipping sequence of 8 bits compared to the 11 bits chipping sequence of Barker Code.

What are complementary codes?

Abstract. Complete complementary codes represent special group of codes with unique properties, which were not detected for any other codes. These codes found a wide application in several science areas with the broadest application possibilities in telecommunications.

What modulation technique does 802.11 b wireless use?

complementary code keying
Technically, the 802.11b standard uses complementary code keying (CCK) as its modulation technique, which uses a specific set of length 8 complementary codes that was originally designed for OFDM but was also suitable for use in 802.11b because of its low autocorrelation properties.

What is DSSS and CCK modulation scheme?

➨ CCK and DSSS are spread spectrum modulation techniques which provides high security during transmission due to presence of information below noise level. OFDM achieves spreading of data by transmitting large number of carriers, each at low data rate.

What is the benefit of using complementary code keying CCK )?

Beside shorter chipping sequence, CCK also has more chipping sequences to encode more bits (4 chipping sequences at 5.5 Mbit/s and 8 chipping sequences at 11 Mbit/s) increasing the data rate even further.

What is the 802.11 g standard?

The 802.11g is a standard for Wireless Local Area Networks (WLANs) and an extension to the 802.11 specification. The 802.11g technology for wireless networks is designed for transmission over short distances. The maximum network bandwidth is 54 Mbps in the 2.4 GHz bands.

What are the two complementary codes?

Chargaff’s rule, also known as the complementary base pairing rule, states that DNA base pairs are always adenine with thymine (A-T) and cytosine with guanine (C-G).

What is complementary subsequence?

In applied mathematics, complementary sequences (CS) are pairs of sequences with the useful property that their out-of-phase aperiodic autocorrelation coefficients sum to zero. Binary complementary sequences were first introduced by Marcel J. E. Golay in 1949.

Which modulation technique is used in DSSS?

In telecommunications, direct-sequence spread spectrum (DSSS) is a spread-spectrum modulation technique primarily used to reduce overall signal interference. The direct-sequence modulation makes the transmitted signal wider in bandwidth than the information bandwidth.

What is complementary code keying ( CCK ) used for?

Complementary code keying (CCK) is a modulation scheme used with wireless networks (WLANs) that employ the IEEE 802.11b specification.

When do you use complementary code keying in 802.11?

CCK is a variation and improvement on M-ary Orthogonal Keying and uses ‘polyphase complementary codes’. They were developed by Lucent Technologies and Harris Semiconductor and were adopted by the 802.11 working group in 1998. CCK is the form of modulation used when 802.11b operates at either 5.5 or 11 Mbit/s.

What’s the difference between Barker and complementary codes?

In complementary codes, the number of pairs of identical elements, called like elements, in one sequence is equal to the number of pairs of unlike elements in the other sequence having same separation. CCK has a shorter chipping sequence of 8 bits compared to the 11 bits chipping sequence of Barker Code.

When was polyphase complementary code keying invented?

CCK is a variation and improvement on M-ary Orthogonal Keying and uses ‘polyphase complementary codes’. They were developed by Lucent Technologies and Harris Semiconductor and were adopted by the 802.11 working group in 1998.