PI/4-DQPSK phase state encoder/decoder
Patent 5438592 Issued on August 1, 1995. Estimated Expiration Date: 
March 31, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 31, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3336578 3409831 System for synthesizing a modulated signal Patent #: 5077757 InventorAssigneeApplicationNo. 221632 filed on 03/31/1994US Classes:375/283, Differential phase shift keying (diphase)375/279Phase shift keyingExaminersPrimary: Chin, StephenAssistant: Luu, Chuong Anh International ClassesH04L 027/10H04L 027/18 AbstractA π/4-DQPSK differential phase state encoder/decoder (Codec) is presented which can be implemented using a small number of logic gates. The phase state Codec acts upon data in the transmitter and in the receiver of a π/4-DQPSK modulating system whereby the use of a look-up table technique or other off-line procedure to ensure proper phase transitions is not required. The phase state Codec is configured to ensure compliance with the IS-54 standard as well as other similar standards. | |
