Continuous phase modulation

About: Continuous phase modulation is a research topic. Over the lifetime, 3199 publications have been published within this topic receiving 37245 citations. The topic is also known as: CPM.

Space-time coding using MSK

Abstract: Recent papers have shown that space-time (ST) coding using continuous phase modulation has a number of advantages relative to linear modulation, among which is its constant envelope, which allows transmission with inexpensive and power-efficient Class C amplifiers. The present paper presents a particularly simple variant, ST coding based on minimum shift keying (MSK), an offset format. ST codes with offset modulation give much better performance than quadrature phase shift-keying (QPSK), for the same number of states, and the MSK ST decoding computational load is smaller than that of QPSK by a ratio that improves exponentially with the number of transmitter antennas. The relationship between offset and nonoffset modulation formats is explored and the effect of pulse shape is shown explicitly.

A Frequency Tunable 360° Analog CMOS Phase Shifter With an Adjustable Amplitude

Abstract: This brief presents a new vector sum phase shifter topology utilizing a current mode ${R}$ - ${C}$ poly phase filter along with several current steering variable gain amplifiers. The phase shifter performs all the tasks of vector generation, gain control, and vector summation in a single block (phase shifter core) to save power and area. The phase shifter core provides 360° of continuous phase tuning with an adjustable amplitude while consuming only 0.063 mm2 of on-chip area. The phase shifter can generate a signal with a tunable phase and magnitude in a phased array, thereby providing a better control over the beamwidth and sidelobe levels. The circuit is frequency reconfigurable, and its center frequency can be tuned within 26–28 GHz with an instantaneous bandwidth of 3 GHz. The phase shifter, fabricated in 130-nm CMOS technology, occupies an area of 0.284 mm2 (excluding the pads) and consumes 27 mW of power. The phase shifter’s RMS phase and gain errors for 64 measured phase states are less than 2.6° and 0.31 dB, respectively, within the 3-dB bandwidth. The measured IP1dB and IIP3 are larger than −9.8 and 0 dBm, respectively. This phase shifter is a good candidate for automotive radar as well as 5G applications.

Multi-carrier spread spectrum device using cyclic shift orthogonal keying, transmitter, receiver, and communication system thereof

Abstract: A multi-carrier spread spectrum device using cyclic shift orthogonal keying includes: a modulation unit for receiving a first part of data bits and transforming the first part of data bits to a modulation symbol d i by modulation; a cyclic-shift unit for receiving a base code c (0) and a second part of data bits, and performing a cyclic-shift to the base code c (0) in accordance with the second part of data bits to generate a CSOK symbol c (m i ) ; and a multiplier for multiplying the modulation symbol d i by the CSOK symbol c (m i ) to generate a spread spectrum signal c i .

QPSK Suppressed carrier with rotating reference phase

Abstract: A suppressed carrier signal is offset quadrature phase shift key modulated so the reference carrier phase is stepped 90° in the same direction in synchronism with sequential bits of a serial data stream and is further bi-phase modulated in response to the binary data source having first or second binary values. A coherent receiver responds to the suppressed carrier signal to establish an equivalent sequence of stepping reference phases at the carrier frequency. The reference phases synchronously rotate in 90° increments in the same direction as the suppressed carrier reference, being permitted a four-fold initial phase ambiguity (0°, 90°, 180°, and 270°). The rotating reference phase is compared in a bi-phase manner with the appropriate component of the suppressed carrier signal to derive sequential d.c. polarities indicative of the binary bit values during the sequential binary data bits.