Topic
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.
Papers published on a yearly basis
Papers
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TL;DR: A sequence estimation algorithm for the differential detection of the continuous phase modulation (CPM) signals, yielding significant gains in BER performance and with considerable resistivity to fading, is introduced and makes the proposed receiver useful for land mobile radio and mobile-satellite communications.
Abstract: A sequence estimation algorithm for the differential detection of the continuous phase modulation (CPM) signals, yielding significant gains in BER performance and with considerable resistivity to fading, is introduced. These advantages, along with the reduced hardware complexity, low cost, and fast synchronization which characterize the differential detector, make the proposed receiver useful for land mobile radio and mobile-satellite communications. The new receiver is based on multiple differential detection. The multiple differential detection strategy provides the decoder with more information regarding the transmitted data and applies a noise decorrelation process on the received signal, useful to the sequence estimation. The algorithm is derived in a general form, and can be applied on any CPM scheme, with any degree of complexity. The authors have evaluated the receiver for two of the most popular CPM schemes, the tamed frequency modulation (TFM) and Gaussian minimum-shift keying (GMSK) (with B/sub 1/T=0.25), in the presence of additive white Gaussian noise (AWGN) and Rician fading. The BER performance evaluation results indicated significant gains and considerable reduction of error floors. In AWGN improvements close to 9 dB have been verified. >
26 citations
Patent•
01 Nov 1988TL;DR: In this article, a continuous microstrip phase shifter suitable for use in a phased array microwave hyperthermia system operating at 915 MHz is provided, which utilizes a three dB quadrature hybrid coupler in conjunction with microstrip lines to change the phase of a transmitted wave.
Abstract: A continuous microstrip phase shifter suitable for use in a phased array microwave hyperthermia system operating at 915 MHz is provided. The phase shifter utilizes a three dB quadrature hybrid coupler in conjunction with microstrip lines to change the phase of a transmitted wave. The phase change is introduced through the reflection ports of the coupler which are loaded with identical parallel resonant circuits. An abrupt junction varactor capacitance in parallel with a distributed inductance forms a voltage-tunable resonant circuit. The resonant element values are chosen to give a specified continuous phase variation with minimum transmission loss. This is accomplished without additional microwave circuit elements.
26 citations
Patent•
15 Feb 1989
TL;DR: In this article, a modulated carrier is received on a node (10) and then the I- and the Q-channels extracted with a local carrier clock (16) that is free-running relative to the modulated carriers.
Abstract: A modulated carrier is received on a node (10) and then the I- and the Q-channels extracted with a local carrier clock (16) that is free-running relative to the modulated carrier. The I- and the Q-channels are then input to a digital signal processor (26) wherein a composite phase signal is generated representing the phase difference between the modulated carrier and the local carrier clock (16). The composite phase is output from a look-up table in an EPROM (30) and then the free-running phase the local carrier clock (16) and the modulated carrier is discriminated from the composite phase. The free-running phase is then subtracted from the composite phase to yield the phase modulation on the carrier.
26 citations
22 Oct 2000
TL;DR: The theoretical and measured performance of the multi-h CPM waveform as well as the implementation of a suitable trellis demodulator are described.
Abstract: Multi-h continuous phase modulation (CPM) offers significant improvements over both legacy telemetry waveforms (PCM/FM) and the newly-introduced waveform (Feher (International Telemetering Conference, Las Vegas,p.27-30, 1997) patented FQPSK) in terms of spectral containment and detection efficiency, while retaining a constant envelope characteristic. This paper describes the theoretical and measured performance of the multi-h CPM waveform as well as the implementation of a suitable trellis demodulator.
26 citations
TL;DR: An approach to reduced-complexity detection of partial response continuous phase modulation (CPM) on a linear multipath channel is presented and it is shown that for channels with a long memory, a significant complexity reduction can be achieved at the cost of a moderate degradation in performance.
Abstract: An approach to reduced-complexity detection of partial response continuous phase modulation (CPM) on a linear multipath channel is presented. The method, referred to as decision feedback sequence estimation (DFSE), is based on a conventional Viterbi algorithm (VA) using a reduced-state trellis combined with decision feedback (DF). By varying the number of states in the VA, the receiver structure can be changed gradually from a DF receiver to the optimal maximum-likelihood sequence estimator (MLSE). In this way different tradeoffs between performance and complexity can be obtained. Results on the receiver performance, based on minimum distance calculations and bit error rate simulations, are given for Gaussian minimum-shift keying modulation on typical mobile radio channels. It is shown that for channels with a long memory, a significant complexity reduction can be achieved at the cost of a moderate degradation in performance. >
26 citations