Yuping Zhao

• Peking University

Classical source polar codes require the construction of frozen sets for given sources. While this scheme offers excellent theoretical performance, it faces challenges in practical data compression systems, including sensitivity to the accuracy and computational complexity of the construction algorithm. In this letter, we explore the feasibility of...

Semantic communication (SemCom) has emerged as a promising architecture in the realm of intelligent communication paradigms. SemCom involves extracting and compressing the core information at the transmitter while enabling the receiver to interpret it based on established knowledge bases (KBs). This approach enhances communication efficiency greatl...

Semantic Communication (SemCom) is envisaged as the next-generation paradigm to address challenges stemming from the conflicts between the increasing volume of transmission data and the scarcity of spectrum resources. However, existing SemCom systems face drawbacks, such as low explainability, modality rigidity, and inadequate reconstruction functi...

This letter investigates the challenges encountered by deep joint source-channel coding in erasure channels. We explore the effectiveness of the widely adopted dropout technique in endowing deep neural networks with resilience against erasures. However, directly applying dropout at the channel layer introduces uncertainty into the neural network’s...

The rapidly evolving field of generative artificial intelligence technology has introduced innovative approaches for developing semantic communication (SemCom) frameworks, leading to the emergence of a new paradigm-generative SemCom (GSC). However, the complex processes involved in semantic extraction and generative inference may result in consider...

Semantic communication (SemCom) has emerged as a promising architecture in the realm of intelligent communication paradigms. SemCom involves extracting and compressing the core information at the transmitter while enabling the receiver to interpret it based on established knowledge bases (KBs). This approach enhances communication efficiency greatl...

Due to the serious path loss of millimeter-wave (mmWave), the signal sent by the base station is seriously attenuated when it reaches the indoors. Recent studies have proposed a glass-based metasurface that can enhance mmWave indoor signals. The transparent reconfigurable intelligent surface (RIS) focuses on the mmWave signal to a specific location...

In reconfigurable intelligent surface (RIS)-assisted wireless communication systems, adjusting the phase shift of RIS unit cells is crucial for improving communication performance. Due to massive RIS unit cells, the number of phase shift parameters fed back from the base station (BS) to the RIS is enormous, which occupies a large number of frequenc...

Abstract A latest coding scheme named polarization‐adjusted convolutional (PAC) codes is shown to approach the dispersion bound for the code (128,64) under list decoding. However, to achieve the near‐bound performance, the list size of list decoding needs to be excessively large, which leads to insufferable time complexity. In this paper, to improv...

Oscillator phase noise is one of the bottlenecks that limits the self-interference (SI) cancellation capability of full-duplex systems. In this paper, we propose a method for the suppression of common phase error (CPE) and intercarrier interference (ICI) induced by the phase noise in full-duplex orthogonal frequency division multiplexing (OFDM) sys...

Reconfigurable intelligent surface (RIS) has emerged as a promising technique for enhancing the performance of wireless networks. However, the traditional reflecting‐only RIS requires that the transmitter and receiver ought to be on the same side of the RIS, limiting the flexibility of RIS deployment. To overcome this drawback, a new simultaneous t...

The sixth generation advocates green communications, thus energy efficiency (EE) has become an important metric. In this study, a method to increase the EE of a reconfigurable intelligent surface (RIS) aided point‐to‐point communication system is proposed, where both sources are equipped with multi‐antenna and operate in the full‐duplex (FD) mode....

In this letter, we investigate the joint beamforming optimization for a reconfigurable intelligent surface (RIS)-aided multi-antenna full-duplex communication system. Our goal is to minimize the total transmit power by jointly optimizing the active beamforming at the sources and the passive beamforming at the RIS, subject to the minimum data rate r...

This letter considers the secure communication in a reconfigurable intelligent surface (RIS) aided full duplex (FD) system. A FD base station (BS) serves an uplink (UL) user and a downlink (DL) user simultaneously over the same timefrequency dimension assisted by a RIS in the presence of an eavesdropper. In addition, the BS transmits artificial noi...

In this letter, we study the reconfigurable intelligent surfaces (RIS) aided full-duplex (FD) communication system. By jointly designing the active beamforming of two multi-antenna sources and passive beamforming of RIS, we aim to maximize the energy efficiency of the system, where extra self-interference cancellation power consumption in FD system...

This work studies the effectiveness of a novel simultaneous transmission and reflection reconfigurable intelligent surface (STAR-RIS) aided Full-Duplex (FD) communication system. We aim to maximize the energy efficiency by jointly optimizing the transmit power and passive beamforming at the STAR-RIS. We propose an efficient algorithm to optimize th...

This work demonstrates the effectiveness of a novel simultaneous transmission and reflection reconfigurable intelligent surface (STAR-RIS) in Full-Duplex (FD) aided communication system. The objective is to minimize the total transmit power by jointly designing the transmit power and the transmitting and reflecting (T&R) coefficients of the STAR-RI...

Reconfigurable intelligent surface (RIS) has been proven to be a promising technology for improving the performance of future wireless systems. However, since conventional RIS can only reflect or transmit (i.e., refract) incident signals, it limits the applications of RISs. Fortunately, a novel simultaneous transmission and reflection reconfigurabl...

Beamforming technology is widely used in millimeter wave systems to combat path losses, and beamformers are usually selected from a predefined codebook. Unfortunately, the traditional codebook design neglects the beam squint effect, and this will cause severe performance degradation when the bandwidth is large. In this letter, we consider that a co...

The development of a low-cost and portable integrated sensing system for hydrogen peroxide could offer exciting opportunities for the diagnosis of diseases, and environmental monitoring. Arduino is a popular platform with integrated software and hardware, and a large number of open source sensor libraries. Here, we show the development of a new hom...

Abstract Puncturing and shortening are two common ways to achieve rate‐compatible non‐systematic polar codes (NSPCs). Systematic polar codes (SPCs) have been shown to outperform NSPCs with the same encoding and decoding complexity. However, rate‐compatible SPCs have never been comprehensively studied in previous work. In this paper, two rate‐compat...

Channel estimation for millimeter wave (mmWave) systems is challenging due to their large antenna arrays. Owing to the sparse scattering nature of the mmWave channel, channel estimation can be performed by estimating the directions and the gains of paths. Most existing schemes assume that a wideband mmWave channel exhibits a common sparsity in the...

Beamforming technology is widely used in millimeter wave systems to combat path losses, and beamformers are usually selected from a predefined codebook. Unfortunately, traditional codebook design neglects the beam squint effect, and this will cause severe performance degradation when the bandwidth is large. In this letter, we consider that a codebo...

A latest coding scheme named polarization-adjusted convolutional (PAC) codes is shown to approach the dispersion bound for the code (128,64) under list decoding. However, to achieve the near-bound performance, the list size of list decoding needs to be excessively large, which leads to insufferable latency. In this paper, to improve the speed of li...

We propose a nonuniform quantized decoder for polar codes. The design metric of the quantizers is to minimize the distortion incurred by quantization. The quantizers are obtained via dynamic programming and the optimality of the quantizer is proved as well. Simulation results show that the error correction performance degradation of the proposed no...

We propose a nonuniform quantized decoder for polar codes. The design metric of the quantizers is to minimize the distortion incurred by quantization. The quantizers are obtained via dynamic programming and the optimality of the quantizer is proved as well. Simulation results show that the error correction performance degradation of the proposed no...

Polar codes are known as the first capacity-achievable codes with low encoding and decoding complexity. The sequential decoding nature of traditional polar decoding algorithms such as successive cancellation (SC) results in high decoding latency, which is not suitable for services that require high reliability and low latency. Deep learning for dec...

In millimeter wave (mmWave) communications, the beamforming gains of large-scale antenna arrays are used to combat severe path losses and improve communication link quality. This requires beam training (BT) to determine the optimal beam direction and achieve beam alignment. The hierarchical codebook with multi-resolution training beams is widely us...

Polar codes have been adopted as the control channel coding scheme in the fifth generation new radio (5G NR) standard due to its capacity-achievable property. Traditional polar decoding algorithms such as successive cancellation (SC) suffer from high latency problem because of their sequential decoding nature. Neural network decoder (NND) has been...

The device-to-device (D2D) relay technology is one of the key technologies in 5G networks, and its coverage problem is an important issue for network management. However, the traditional relay coverage theory and existing schemes in D2D relay networks (e.g., based on the received signal-to-interference-plus-noise ratio) are not optimal for D2D rela...

Shortening is a common way to achieve rate-compatible polar codes. The existing shortening algorithms select shortened bits merely according to the structure of the generator matrix in order to make them known by the receiver. In this paper, we take into account the effect that the shortening has on the capacity of split channels and propose a shor...

Hybrid beamforming structure, which consists of digital precoding and analog beamforming, is a low-cost solution to millimeter wave large-scale antenna systems. In this letter, we study the sum rate maximization problem where analog beamformer is selected from a discrete codebook. A two-stage scheme is proposed in order to avoid exhaustive search....

A pair of matched filters whose cascade response satisfies the Nyquist criterion can guarantee the inter-symbol interference (ISI)-free transmission for band-limited communication systems. For a linear phase finite impulse response squareroot Nyquist filter, it is necessary to strike a balance between the stop-band attenuation (SBA) and ISI perform...

The set-top boxes based on the Digital Video Broadcasting -Cable (DVB-C) standard have been deployed worldwide for decades, and the square-root raised cosine (SRRC) filter is specified as its receive filter. Recent years, plenty of the preferable square-root Nyquist filters have been developed. It is eagerly desired to upgrade the filter in DVB-C s...

The 3rd Generation Partnership Project (3GPP) introduces carrier aggregation (CA) technology in LTE-Advanced (LTE-A) systems which admits aggregating different component carriers. As a result, it increases the feedback delay of the channel quality indicator (CQI) from user equipments (UE) to eNodeB. This unavoidable CQI delay lowers the system perf...

This paper proposes a novel approach for full duplex using chaotic sequences which is known as the asynchronous code-division duplex (Async-CDD) system. The Async-CDD system can transmit and receive signals at the same time and in the same frequency channel without time slot synchronization. The data rate of the Async-CDD system is 8 times higher t...

Device-to-device communication can assist cellular networks by making certain users equipment (UEs) work as relays between the base station (BS) and other users. In this paper, we present the ultra-dense network (UDN) with D2D relays instead of small cells, where UEs can form into clusters according to the traffic demand in hot-spot areas. Each UE...

We propose an adaptive resource allocation algorithm for scalable H.264 video transmission over orthogonal frequency-division multiple-access (OFDMA) systems. The algorithm explores the scalability of the video codec and the multiuser diversity of OFDMA systems to achieve enhanced efficiency and video quality. We use the peak signal-to-noise ratio...

Due to the increasing demand for 3D video transmission over wireless networks, managing the quality of experience (QoE) of wireless 3D video clients is becoming increasingly important. However, the variability of compressed 3D video bit streams and the wireless channel condition as well as the complexity of 3D video viewing experience assessment ma...

Hybrid cognitive radio (CR) relays serve cellular users in a two-hop fashion to improve the network capacity-the communication with base station (BS) operates in cellular spectrum, while that with users operates in unlicensed spectrum for dynamic spectrum access. In this letter, we present a user association framework that optimizes the overall sys...

In order to further improve the packet data service performance, the Continuous Packet Connectivity (CPC) mode has been proposed as a configuration in 3GPP Rel'07. For the burst type data, even in the case of no data transmission, the frequent power control signaling also needs to be performed, which brings considerable overhead to system and incre...

Given the enormous demands for location based applications and service, localization technologies, which estimate accurate locations of the mobile users, have been developed rapidly outdoors (e.g., GPS) and indoors (e.g., WiFi fingerprinting). However, in half-open areas where existing studies are rarely conducted, either the outdoor or indoor loca...

In wireless video transmission, encoded video frames are often transmitted with certain delay and reliability constrain. Due to the limited wireless bandwidth, time-variant channel conditions and the fluctuant video frame rate, it is difficult to allocate transmission resources to guarantee online video quality. In this paper, we propose a fuzzy lo...

We propose a training-aided inter-frame iterative frequency offset estimation (IIFOE) method for CO-OFDM system, the complexity of which is significantly reduced by only estimating sign of FO in each iteration.

A concatenated coded modulation communication system and method combines Trellis Coded Modulation with non-Gray code constellation mapping, interleaving, and non-binary Low Density Parity Check coded channel modulation with Gray code constellation mapping to improve error performance.

We propose an efficient channel estimation method based on weighted inter-frame averaging for CO-OFDM system. Up to 2.4 dB error vector magnitude improvement compared with traditional methods is shown by a PDM-16QAM CO-OFDM experiment.

The number of mobile subscribers has increased by 399 million in 2013, of which WCDMA/HSPA subscribers account for 68%. Meanwhile, various short-size packet services, such as web browsing, instant messaging and social network applications, are growing rapidly, leading to a sharp increase in signaling load and limit the network capacity to allocate...

We propose an efficient channel estimation method for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) based on weighted inter-frame averaging (WIFA), in which the channel estimation results of the adjacent frames are averaged to increase the estimation accuracy. The principle of the proposed WIFA method is theoretically analyz...

To verify the performance of communication systems, software and hardware prototypes are widely used. However, with the increasing complexity of communication systems, software prototypes cannot meet the needs of real-time operations while hardware prototypes are expensive and time-consuming to develop. Nowadays, Graphics Processing Unit (GPU) show...

This paper presents a DDC (digital down converter) on NVIDA 580 GTX, which consists of a DDS (direct digital synthesizer), a CIC (cascade integrator comb) decimation filter and a FIR (finite impulse response) filter. The decimating factor of the CIC decimation filter can be arbitrary positive integer and the major concern is concentrated on how to...

A novel energy efficient heterogeneous networks (HetNet) deployment scheme is proposed in this paper. Unlike the traditional deployment, we consider the scenario with picocell eNodeB (PeNB) at the edge instead of under the umbrella of macrocells in HetNet. In the novel scheme, one PeNB with directional antennas is deployed on the border of neighbor...

With the development of communication systems, the requirement for efficient error correcting code becomes an important issue. In this paper, we address a parallel software implementation of BCH(Bose-Chaudhuri-Hocquenghen) decoding for HINOC (High Performance Network Over Coax) standard, which is an access network technology aiming at solving the b...

Two-way relaying in wireless systems has initiated a large research effort during the past few years. Nevertheless, it represents only a specific traffic pattern and it is of interest to investigate other traffic patterns where such a simultaneous processing of information flows can bring performance advantage. In this paper we consider a four-way...

We propose a weighted inter-frame averaging channel estimation method for CO-OFDM transmission system. Simulation results show that the proposed method has better performance than LS and ISFA methods at the same spectral efficiency.

We propose a framework for efficient scalable video multicast over downlink orthogonal frequency-division multiplexing (OFDM) systems with multiple transmit antennas. In conventional video multicast systems, the achievable transmission rate is determined by the user with the worst channel condition, and the system saturates the capacity when the nu...

In this paper we consider a four-way relaying multiple-input multiple-output (MIMO) scenario, where each of the two Mobile Stations (MSs) has a two-way connection to the same Base Station (BS), while each connection is through a dedicated Relay Station (RS). The RSs are placed in such a way that one RS and the terminals associated with it do not in...

Two-way relaying in wireless systems has initiated a large research effort during the past few years. In particular, structured codes and lattices are instrumental for achieving high rates when using Physical Layer Network Coding (PLNC). In an attempt to bring the gains of PLNC beyond the classical traffic pattern of two-way relaying, in this paper...

This paper studies the suppression of frequency- hopping (FH) narrowband interference (NBI) in spread-spectrum (SS) systems. Existing NBI suppression algorithms focus on the case that the center frequency of the NBI is invariant and the performance degrades severely when the NBI is frequency-hopping. In this paper, an FH-NBI suppression algorithm i...

In this paper, we develop a cross-layer design incorporating adaptive modulation coding (AMC) and truncated hybrid automatic repeat request (HARQ). We define different packet error rate (PER) constraints for each (re)transmission, thus adopting dynamic switching thresholds correspondingly to fully exploit the combining gain in HARQ protocols. Analy...

This paper proposes a narrowband interference (NBI) suppression algorithm for Direct Sequence-Code Division Multiple Access systems. The NBI is considered from heterogeneous networks, and predicted based on its cyclostationary characteristic using a nonlinear feed-forward neural network predictor which eliminates the nonlinearity of the spread spec...

In this paper, we propose a cross-layer design combining adaptive modulation coding (AMC) and automatic repeat request (ARQ) to minimize the bit energy consumption under both packet loss rate and retransmission delay constraints. We analyze the best constellation size of M-ary square quadrature amplitude modulation (MQAM) in different distance, and...

In RFID system, reducing the frequency of collisions is very important for fast tag identification. In this paper, we proposed a pre-split anti-collision algorithm based on binary tree algorithm. The proposed scheme pre-splits the tags into different groups before the reader detects the first tag. Simulation results indicate that the modified algor...

Two-way relaying in wireless systems has initiated a large research effort during the past few years. While one-way relay with a single data flow introduces loss in spectral efficiency due to its half-duplex operation, two-way relaying based on wireless network coding regains part of this loss by simultaneously processing the two data flows. In a b...

Along with the rapid progress of Internet technologies, Instant Messaging (IM) has become increasingly popular due to its social functionalities. Despite its prevalence, little has been done to analyze the characteristics of the conversational pattern among IM users. In this paper, we establish an ON/OFF model to simulate single user conversations...

In this letter, we propose a framework for scalable video multicast, which exploits the scalability of scalable video and the multiuser diversity of OFDMA systems. We further propose a resource allocation algorithm which guarantees the base-quality video for all users, and improves the transmission efficiency for users with good channel conditions.

Narrowband interference from other systems degrades greatly the performance of Orthogonal Frequency Division Multiplexing (OFDM) systems in heterogeneous networks. This paper proposes a cyclostationarity-based narrowband interference suppression algorithm to estimate and suppress the interference, and derives the Signal to Interference plus Noise R...

The release of IEEE 802.15.4 medium access control (MAC) and physical layer specifications represents a significant milestone in promoting deployment of wireless sensor networks. This paper first analyzes the performance of the contention access period (CAP) specified in the IEEE 802.15.4 standard by integrating the discrete-time Markov chain model...

A Relay Station (RS) uses a buffer to store and process the received data packets before forwarding them. Recently, the buffer has been exploited in one-way relaying to opportunistically schedule the two different links according to their channel quality. The intuition is that, if the channel to the destination is poor, then RS stores more data fro...

Supporting the quality of service of unlicensed users in cognitive radio networks is very challenging, mainly due to dynamic resource availability because of the licensed users' activities. In this paper, we study the optimal admission control and channel allocation decisions in cognitive overlay networks in order to support delay sensitive communi...

In this paper, we investigate feedback compression for a general multiple-input multiple-output (MIMO) system over time-correlated Rayleigh block-fading channels. With a channel state transition graph characterized by Markov chain, we first compress channel state information (CSI) feedback through Huffman coding. We then propose a threshold based a...

The issue of Co-Channel Interference (CCI) in the Orthogonal Frequency Division Multiplexing (OFDM) systems is studied in this paper. A time-domain estimation and elimination scheme of sinusoidal-modeled CCI is proposed based on the Minimum Mean Square Error (MMSE) criterion. It is proved by simulation that the proposed algorithm can suppress the C...

Frequency offset can deteriorate the performance of wireless communication systems seriously. In this paper, the effect of frequency offset caused by the error of local oscillator or the time variation of the channel is studied for cyclic prefix-code division multiple access (CP-CDMA), cyclic prefix-comb spectrum-CDMA (CP-CS-CDMA) and orthogonal fr...

In these years, the living quality of elderly is drawing more and more attention. In order to meet their needs for Internet we have designed tailored easy access Internet browser for tablet computers. The system integrates wireless network connection with the new Internet browser, and runs on Android OS which is currently widely used on tablet comp...

In this paper we inspect remote health care, and especially alert call concept and usability design for Chinese Chronic Obstructive Pulmonary Disease (COPD) patients. Generally, remote health care can facilitate cost efficient and improved treatment and follow-up of various illnesses. For service providers it can offer expanded service palette, ena...

In this paper, a group-wise joint detection (JD) algorithm is proposed for dual rate time division-synchronization code division multiple access (TD-SCDMA) systems. The proposed algorithm first groups users based on their data rates and then deals with them group by group starting from the group of high data rate users (HRUs). Simulation results il...

In this paper, we proposed a new velocity estimation algorithm for orthogonal frequency division multiplexing (OFDM) systems, which is based on the variance of channel frequency response (CFR) of two adjacent OFDM symbols. The proposed algorithm can fast and accurately estimate the velocity in both Rayleigh and Rician fading channels, and is low in...

In Orthogonal Frequency Division Multiplexing (OFDM) systems, there are large estimate errors of the received power in a traditional Automatic Gain Control (AGC). This paper proposes a distribution-function-based AGC method. This method estimates the received power by using the distribution function of the output signal from the Analog to Digital C...

This paper investigates the problem of single-tone jamming in orthogonal frequency division multiplexing (OFDM) systems. A frequency-domain estimation and elimination scheme for single-tone interference is proposed. The proposed scheme is independent of any pilot or vacant sub carrier. Simulation results demonstrate that the proposed method is supe...

In orthogonal frequency division multiplexing (OFDM) systems, the estimate errors of automatic gain control (AGC) and DC estimation (DCE) are larger than in single carrier systems. It is due to the fact that OFDM signals have Gaussian distributions. Consequently, estimate errors will occur in the AGC and the DCE because of the truncating effect gen...

Proper admission control in cognitive radio networks is critical in providing QoS guarantees to secondary unlicensed users. In this paper, we study the admission control and channel allocation problem in overlay cognitive radio networks under the maximum cumulative delay constraint. We formulate it as a Markov decision process problem, and then sol...

The cyclic prefix comb spectrum code division multiple access (CP-CS-CDMA) has comb spectrum in frequency domain. Its different code groups can be separated with a simple hopping accumulator. In the paper, we combine OFDMA and CP-CS-CDMA, and propose a new multiple access scheme, hybrid multiple access (HMA). Then we propose a new reuse partitionin...

When an IEEE 802.15.4 network has many nodes and is almost saturated, the probability of collision is large, and the throughput is small. The main reasons are the adoption of slotted CSMA/CA and the mechanism that if a data transmission cannot be completed before the end of contention access period (CAP), it has to wait until the start of the CAP i...