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A 450kHz 30kbps all-digital BPSK demodulator is implemented in 65nm CMOS. Correlation and carrier recovery algorithms are designed to be PVT-aware through digital correction. The target BER of 10−6 is achieved through 16 symbol per bit redundancy with 8× oversampling. An 8-bit tunable oscillator is utilized with corresponding frequency and phase locking techniques to maintain packet synchronization...
The application of multi-symbol detection (MSD) algorithm in PCM/FM system improves demodulation performance, but also causes the system more sensitive to the carrier frequency offset deviation, which means the same deviation will lead to greater loss of performance in PCM/FM system based on MSD. Former carrier synchronization methods are no longer suitable due to its poor performance in low SNR,...
Direct conversion digital receivers require precise sample timing in order to synchronize them with the carrier waves of received RF signals. This means a carrier regeneration technique for modulated RF signals is required. Unfortunately, carrier regeneration is considered to be very difficult to apply in the case of 64-QAM signals. To address this problem, we have developed a sampling clock generator...
A novel RF quadrature under-sampling technique, which we have developed, makes it possible to extract baseband inphase (I) and quadrature (Q) data from an RF signal directly. The technique is applicable to advanced modulations, such as demodulating an OFDM without losing any vector information. Its only drawback is that it requires a precise sampling frequency and timing to be synchronized with the...
In this paper, a new kind of COFDM demodulator is proposed, which is conforming to the European DVB-T standard. The proposed prototype mainly contains four blocks: time synchronization, frequency synchronization, 2 K/8 K FFT processor, and channel estimation. Each block is implemented by the relatively simple algorithm to avoid the overhead of hardware complexity.
This paper presents a BFSK demodulation method using discrete short-time Fourier transform (DSTFT). The method discusses the BFSK signal in time-frequency domain, which is different from conventional demodulation methods. The principle of demodulation and a new code synchronization algorithm are given in the paper, different window functions are tried during the simulation, which bring different demodulated...
This paper designs and accomplishes a fast frequency hopping system with 40 Khps based on the software radio. The paper presents several innovational techniques for realizing hopping system, such as frequency hopper, frequency hopping sequence, bit synchronization, hopping pattern synchronization, hopping signal demodulation, etc. Then the paper presents system's detailed hardware/software architecture...
In the high-speed wireless communication, by the frequency difference impact, it took longer time to capture the carrier and to establish the symbol synchronization within the demodulation. Given the characteristics of pi/4 -DQPSK modulation and frequency-hopping communication, which were widely used in the wireless communication, the algorithm of the rapid signal capture and synchronization recognition...
We propose a more accurate method to analyze multilevel frequency-shift-keying frequency-hopping code-division multiple-access (MFSK/FH-CDMA) wireless communication systems using ldquoone-hitrdquo FH patterns, instead of random FH patterns. By also removing the over-optimistic symbol-synchronous assumption, the new method provides a more realistic performance analysis as the MFSK modulation may result...
Correlative minimum shift keying (MSK), a second order polynomial modulation scheme known as tamed frequency modulation (TFM), is a constant envelope type of modulation with a perfect peak to average power ratio (PAPR), besides the property of low out of band power. We apply the linearized TFM to the single carrier transmission with frequency domain equalization (SC/FDE) concept. We then obtain a...
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