Showing papers on "SC-FDE published in 2007"
23 Apr 2007
TL;DR: A concept similar to the standard FMCW (frequency-modulated continuous wave) radar principle is used to estimate the offset in time and in frequency between two wireless communication units, allowing for a synchronization of both offsets significantly below 100 ps and 10 Hz.
Abstract: In this paper we present a novel approach for high precision clock synchronization in wireless systems. A concept similar to the standard FMCW (frequency-modulated continuous wave) radar principle is used to estimate the offset in time and in frequency between two wireless communication units. The novel approach allows for a synchronization of both offsets significantly below 100 ps and 10 Hz, respectively. This highly accurate synchronization is used in a prototype system to measure the distance between wireless units similar to a secondary radar. The prototype works within the 5.8 GHz ISM-band and uses a bandwidth of 150 MHz. With the setup presented we can measure the distance between two radio units with a standard deviation of 4 to 5 cm over a range of 200 m. This distance deviation implies a clock and center frequency synchronization of both communication modules significantly below 100 ps and 1 ppb, respectively. The broadband measurement principle is robust towards multi-path interference. It can be extended to other frequency bands and is well-suited for direct integration into communication channels and novel modulation principles such as OFDM (orthogonal frequency division multiplexing) or SC/FDE (single carrier transmission with frequency domain equalization), e.g. for locatable WLAN (wireless local area network) devices or wireless sensor networks
48 citations
TL;DR: The results show that NBI can be effectively suppressed by transmitting and matched filtering the pulse with a spectral null at the interference frequency, therefore improving the robustness of UWB systems to NBI.
Abstract: This paper investigates spectrum shaping in ultra-wideband (UWB) communications in order to introduce spectral nulls to limit interference with narrowband signals. Each transmitted symbol is represented by a "coded Gaussian monocycle pulse" in which Gaussian monocycles are weighted, delayed and summed in accordance with a designed codeword. The use of the Gaussian monocycle ensures that the UWB spectrum mask established by the Federal Communications Commission (FCC) is met, and the codeword is designed to generate a spectral null at the frequency or frequencies being used by existing narrowband devices. Signals obtained with different spectrum shapings (e.g., Butterworth, Chebyshev, elliptical) and by introducing nulls at multiple interference frequency bands are discussed. This approach can be used in various systems; as one application, we simulate the performance of a coded monocycle UWB system with a spectral null in the presence of narrowband interference (NBI) using single carrier block transmission with frequency domain equalization (SC-FDE), and compare its performance with that of an uncoded SC-FDE UWB system using a single Gaussian monocycle. Our results show that NBI can be effectively suppressed by transmitting and matched filtering the pulse with a spectral null at the interference frequency, therefore improving the robustness of UWB systems to NBI
38 citations
TL;DR: This paper investigates single-carrier frequency-domain equalization in combination with multi-input multi-output (MIMO) technology and proposes two novel FDE-MIMo structures, which are referred to as FDE with noise prediction (FDE-NP) and Fde-NP with successive interference cancellation (F DE-NP-SIC).
Abstract: Single-carrier frequency-domain equalization (SC-FDE) has recently been receiving much attention as an attractive method for broadband wireless communications for its advantages such as lower peak-to-average ratio and reduced sensitivity to carrier frequency offsets, when compared with orthogonal frequency-division multiplexing (OFDM) systems. In this paper, we investigate its combination with multi-input multi-output (MIMO) technology and propose two novel FDE-MIMO structures, which we refer to as FDE with noise prediction (FDE-NP) and FDE-NP with successive interference cancellation (FDE-NP-SIC). It is shown that the proposed schemes have lower complexity and achieve better performance and complexity tradeoff than the conventional FDE scheme with decision feedback processing. To evaluate the system performance, we will propose an accurate theoretical analysis based on the modified Chernoff bound (MCB) and show that it is not only applicable to the proposed FDE-NP and FDE-NP-SIC schemes, but also to general MIMO systems with equalization. By using the developed MCB along with simulation results, we will show that the proposed FDE-NP and FDE-NP-SIC schemes can achieve significant performance improvement over the conventional FDE MIMO schemes
32 citations
TL;DR: A novel class of reduced-CP SC/FDE schemes is presented and evaluated, which takes advantage of a special frame structure for replacing "useless" CP redundancy by fully useful channel coding redundancy, with the help of the DDC algorithm.
Abstract: For conventional cyclic prefix (CP)-assisted single-carrier/frequency-domain equalization (SC/FDE) implementations, as well as for orthogonal frequency-division multiplexing (OFDM) implementations, the CP length is known to be selected on the basis of the expected maximum delay spread. Next, the data block size can be chosen to be large enough to minimize the CP overhead, yet small enough to make the channel variation over the block negligible. This paper considers the possibility of reducing the overall CP assistance, when transmitting sequences of SC blocks, while avoiding an excessively long fast Fourier transform window for FDE purposes and keeping good FDE performances through low-complexity, noniterative receiver techniques. These techniques, which take advantage of specially designed frame structures, rely on a basic algorithm for decision-directed correction (DDC) of the FDE inputs when the CP is not long enough to cope with the time-dispersive channel effects. More specifically, we present and evaluate a novel class of reduced-CP SC/FDE schemes, which takes advantage of a special frame structure for replacing "useless" CP redundancy by fully useful channel coding redundancy, with the help of the DDC algorithm. When using the DDC-FDE technique with these especially designed frame structures, the impact of previous decisions, which are not error-free, is shown to be rather small, thereby allowing a power-efficiency advantage (in addition to the obvious bandwidth-efficiency advantage) over conventional block transmission implementations under full-length CP. Additionally, the DDC algorithm is also shown to be useful to improve the power efficiency of these conventional implementations
26 citations
26 Dec 2007
TL;DR: A frequency-domain multi- packet detection technique for SC-FDE schemes (Single- Carrier with Frequency-Domain Equalization) that allows an efficient packet separation in the presence of successive collisions.
Abstract: Usually, packets involved in a collision are lost, requiring their retransmission. However, the signal associated to collisions has important information concerning the packets involved. In fact, with proper retransmissions we can efficiently resolve collisions. In this paper we propose a frequency-domain multi- packet detection technique for SC-FDE schemes (Single- Carrier with Frequency-Domain Equalization) that allows an efficient packet separation in the presence of successive collisions. This technique allows high throughputs, since the total number of transmissions is equal to the number of packets involved in the collision, even when the channel remains fixed for the retransmissions. Since we consider SC-FDE schemes and the complexity is concentrated in the receiver, this technique particularly appealing for the uplink of broadband wireless systems.
22 citations
TL;DR: This letter proposes a unique-word-based single-carrier system with frequency-domain decision feedback equalization (FD-DFE) for space-time block coded (STBC) transmissions and greatly reduces an error propagation, thus yielding an improved performance as the number of feedback taps increases.
Abstract: This letter proposes a unique-word-based single-carrier (UW-SC) system with frequency-domain decision feedback equalization (FD-DFE) for space-time block coded (STBC) transmissions. The STBC scheme can not be directly applicable to the UW-SC system, because its transmit sequence is reversed in the time-domain. To cope with this problem, we first design a new transmit sequence to fulfill the theorem of circular convolution, and propose a new corresponding receiver structure to have the transmit diversity. Unlike the cyclic prefixed SC system with FD-DFE, the proposed UW-SC system with FD-DFE greatly reduces an error propagation, thus yielding an improved performance as the number of feedback taps increases
21 citations
TL;DR: Simulation results show that the proposed scheme outperforms the interleave- division multiple-access (IDMA) scheme in the block error rate even for severely frequency-selective channel, while providing considerably lower computational complexity.
Abstract: In this letter, we propose a new multiuser detection scheme for single-carrier modulation with frequency-domain equalization (SC-FDE). We first present mathematical formulations of multiuser detection for the SC-FDE system with user- specific interleaving. The proposed structure employs spreader and different interleaver for each user at the transmitter, and re moves multiuser interference with an iterative detection method in the frequency domain at the receiver. Simulation results show that the proposed scheme outperforms the interleave- division multiple-access (IDMA) scheme in the block error rate even for severely frequency-selective channel, while providing considerably lower computational complexity.
19 citations
04 Dec 2007
TL;DR: This paper compares the relative performance of coded single carrier frequency domain equalisation (SC-FDE) and orthogonal frequency-division multiplexing (OFDM) on frequency-selective fading channels, focusing on the extent to which the two schemes can exploit the frequency diversity inherent in such channels.
Abstract: This paper compares the relative performance of coded single carrier frequency domain equalisation (SC-FDE) and orthogonal frequency-division multiplexing (OFDM) on frequency-selective fading channels We focus on the extent to which the two schemes can exploit the frequency diversity inherent in such channels Channels with different impulse response lengths, and therefore available diversity order are considered, with convolutional codes of different rates and constraint lengths, and also turbo-codes We show that on all channels SC-FDE has better performance with codes having smaller minimum distance However with more powerful codes, which enable it to exploit the full frequency diversity available in the channel, OFDM has better performance, particularly on channels with greater diversity
18 citations
TL;DR: Simulation result shows that the proposed system considerably outperforms the distributed space-time block code (D-STBC) SC-FDE over fast fading channels.
Abstract: This letter proposes a relay-based single carrier frequency-domain equalization (SC-FDE) with space-frequency block code (SFBC) in a distributed fashion. The proposed scheme achieves spatial diversity in uplink fast fading channels without the complexity of multiple antennas at source (mobile equipment). The source of the proposed system has a very simple transmitter structure without any increase of peak-to-average power ratio (PAPR). In order to obtain spatial diversity, the transmit sequence of relay is efficiently generated in the time domain, which realizes the SFBC. The corresponding destination structure and frequency domain equalization are also presented. Simulation result shows that the proposed system considerably outperforms the distributed space-time block code (D-STBC) SC-FDE over fast fading channels.
12 citations
TL;DR: By applying the proposed method to MIMO SC-FDE system with insufficient cyclic prefix (CP), the method can significantly improve its error performance, obtaining both the benefits of multiplexing gain and spectral efficiency gain.
Abstract: In this letter, an efficient cyclic prefix reconstruction (CPR) technique with turbo equalization is developed for a multi-input multi-output (MIMO) single-carrier frequency-domain equalization (SC-FDE) system. The proposed method consists of pre-processing estimation (PPE) and residual inter-carrier interference suppression (RICIS). The PPE is employed to compute initial values of MIMO turbo equalization, and the RICIS is used to mitigate residual intercarrier interference (ICI) after each iteration of the CPR. By applying the proposed method to MIMO SC-FDE system with insufficient cyclic prefix (CP), we can significantly improve its error performance, obtaining both the benefits of multiplexing gain and spectral efficiency gain
9 citations
01 Jan 2007
TL;DR: It is shown in the simulation results that Turbo-CPR not only recovers the performance loss due to insufficiency of CP, but also provides extra gains over the lower bound of performance for conventional CP reconstruction schemes.
Abstract: In this paper, a Turbo aided Cyclic Prefix (CP) reconstruction scheme, termed Turbo-CPR, is proposed for Single-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient CP in the transmitter. In Turbo-CPR, the decoder output is incorporated in the process of equalization, i.e. Turbo equalizer is employed. It is shown in the simulation results that Turbo-CPR not only recovers the performance loss due to insufficiency of CP, but also provides extra gains over the lower bound of performance for conventional CP reconstruction schemes.
24 Sep 2007
TL;DR: This paper proposes a technique that allows an efficient packet separation in the presence of successive collisions, considering an SC (Single-Carrier) modulation with FDE (Frequency-Domain Equalization) and a frequency-domain multi-packet detection scheme.
Abstract: Usually, packets involved in a collision are lost, requiring the retransmission of all packets. However, if we do not discard collided packets and we use proper retransmissions we can efficiently resolve collisions. In this paper we propose a technique that allows an efficient packet separation in the presence of successive collisions. We consider an SC (Single-Carrier) modulation with FDE (Frequency-Domain Equalization) and we propose a frequency-domain multi-packet detection scheme. Since our technique requires uncorrelated channels for different retransmissions, we also propose a PS technique (Packet-Shift) for retransmissions using the same channel. Our technique allows high throughputs, since the total number of transmissions is equal to the number of packets involved in the collision. Moreover, the complexity is concentrated in the receiver, making this technique particularly appealing to the uplink of broadband wireless systems. By employing the PS scheme we can use the same channel for the retransmissions, with only a small performance degradation.
15 Oct 2007
TL;DR: It is shown that in an interference-prone system, a combination of orthogonal pilots, spatial processing and Iterative Channel Estimation (ICE) is effective and a promising way to suppress uplink inter-user interference.
Abstract: In this paper, the issue of channel estimation in Single Carrier Frequency Domain Equalization (SC-FDE) uplink Space Division Multiple Access (SDMA) systems in the presence of intra and inter-cell interference is addressed. It is shown that in such an interference-prone system, a combination of orthogonal pilots, spatial processing and Iterative Channel Estimation (ICE) is effective. Adaptive Iterative Block Soft Decision based Feedback Equalizer (IBDFE) with Parallel Interference Cancellation (PIC) assisted Decision Feedback Iterative Channel Estimation is employed. It is shown that such a combination is a promising way to suppress uplink inter-user interference.
04 Dec 2007
TL;DR: It is proposed to compare the performance of fourth-order KF predictor in the most popular block transmission systems: OFDM and SC-FDE systems.
Abstract: Block transmission in wireless communications systems is very sensitive to Carrier Frequency Offset (CFO). In order to reduce the number of pilot symbols used in the estimation of rapidly-varying CFO it was proposed to use a truncated Taylor's series to predict the CFO, where the derivatives up to order d -1 of the series terms are recursively estimated with a d-order Kalman filter (KF). We propose to compare the performance of fourth-order KF predictor in the most popular block transmission systems: OFDM and SC-FDE systems.
14 May 2007
TL;DR: It is shown that if orthogonality between users during their training phase is assured, then good performance is achievable compared to non-orthogonal training and the way to multiplex the training either in time or frequency, does not affect the performance in time-variant channels as long as the orthog onality is maintained.
Abstract: In this paper, the issue of channel estimation with multiple in-cell co-channel users (ICUs) in the presence of out of cell interferers (OCIs) is addressed. A single carrier frequency domain equalization (SC-FDE), uplink space division multiple access (SDMA) system with iterative block decision feedback equalization (IBDFE), based on the soft decisions is considered. To overcome the intra-cell interference, it is shown that if orthogonality between users during their training phase is assured, then good performance is achievable compared to non-orthogonal training. Moreover, we have shown that the way to multiplex the training either in time or frequency, does not affect the performance in time-variant channels as long as the orthogonality is maintained. It is also shown that inter- cell interference could be mitigated with a combination of in-cell orthogonal pilots, spatial diversity and iterative receiver processing. Performance improvement by an IBDFE based on the soft decisions is also shown.
Journal Article•
TL;DR: The MMSE-RISIC equalizer used decisions, acquired from MMSE equalization, to estimate and remove the residual ISI and simulation results show that higher performance can be achieved on frequency selective fading channel.
Abstract: Residual inter-symbol interference(ISI) is the main disadvantage of MMSE equalizer for single carrier frequency domain equalization(SC-FDE) system,so a MMSE(minimum mean-square-error)-RISIC(residual ISI cancellation)decision feedback equalizer was presented for SC-FDE system to eliminate the residual ISI.The MMSE-RISIC equalizer used decisions,acquired from MMSE equalization,to estimate and remove the residual ISI.The computational complexity was very low because only FFT and IFFT were used in the residual ISI estimation.The effect of the equalizer was evaluated in the condition of different channels.Simulation results show that higher performance can be achieved on frequency selective fading channel.
24 Jun 2007
TL;DR: This paper considers a reduced-PMEPR, clipped-OFDM transmission, where an advanced receiver performs the iterative cancellation of the deliberate nonlinear distortion effects, and shows a very significant overall advantage for the SC side.
Abstract: A CP-assisted (cyclic prefix) block transmission is widely accepted as a good choice for future mobile systems, taking advantage of low-cost, flexible, FFT-based (fast Fourier transform) signal processing technology with both OFDM (orthogonal frequency division multiplexing) and SC (single carrier) alternatives. The OFDM alternative provides a simple receiver implementation which allows good performances, by exploiting the channel coding effort, but is known to suffer from a high PMEPR (peak-to-mean envelope power ratio), leading to power amplification difficulties. The SC/FDE (frequency-domain equalization) alternative is easily compatible with low PMEPR values, but the FDE (MMSE) receiver performance is known to be far from the optimum. In this paper, we consider a reduced-PMEPR, clipped-OFDM transmission , where an advanced receiver performs the iterative cancellation of the deliberate nonlinear distortion effects. In parallel, we consider an advanced turbo FDE receiver, as well as simplified iterative FDE receiver implementations, within the SC alternative. The "SC vs OFDM" comparisons of this paper, under the use of iterative receiver techniques in both cases, show a very significant overall advantage for the SC side.
23 Apr 2007
TL;DR: This contribution deals with the synchronization and the fractionally spaced equalization for multiple-input multiple-output (MIMO) single-carrier (SC) systems with frequency domain equalization (FDE).
Abstract: This contribution deals with the synchronization and the fractionally spaced equalization for multiple-input multiple-output (MIMO) single-carrier (SC) systems with frequency domain equalization (FDE). Synchronization, channel estimation and the proposed equalization are evaluated as a system employing real-world over-air transmission in the 2.4 GHz ISM-band by using our current MIMO test-bed (A. Wilzeck et al., 2006). Spatial multiplexing is demonstrated, allowing the system to reach an un-coded net data rate of 28.78 Mbit/s using 8-PSK modulation and a 3-dB bandwidth of 10 MHz
01 Apr 2007
TL;DR: This work applies the linearized TFM to the single carrier transmission with frequency domain equalization (SC/FDE) concept, and obtains a power and bandwidth efficient broadband technique for the SISO and MIMO multipath channels.
Abstract: 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 power and bandwidth efficient broadband technique for the SISO and MIMO multipath channels. Finally we present simulation results.
01 Jan 2007
TL;DR: A PN (Pseudo Noise) based Channel Estimation (CE) algorithm using circular correlation is proposed, and is implemented in Single Carrier Frequency Domain Equalization (SC-FDE) system and it is found that new algorithm has lowest complexity and acceptable performance.
Abstract: A PN (Pseudo Noise) based Channel Estimation (CE) algorithm using circular correlation is proposed, and is implemented in Single Carrier Frequency Domain Equalization (SC-FDE) system The new CE algorithm is compared to typical frequency-domain algorithms, and it is found that new algorithm has lowest complexity and acceptable performance A no-guard-interval PNA-SC-FDE (PN Assisted SC-FDE) system is studied and a simpler receiving procedure for interference-canceling based receiver is proposed Simulation shows that the performance of receiver with interference-canceling and new CE algorithm can approach the performance of receiver with perfect CSI (Channel State Information)
24 Jun 2007
TL;DR: Sub-block processing is proposed, such that joint estimation of the CFO and SFO can be applied and the SC-FDE receiver with proposed closed-loop tracking algorithm is tested on both quasi-static and time-varying multipath fading channels and its effectiveness is demonstrated.
Abstract: With single-carrier frequency-domain equalization (SC-FDE), the carrier-frequency offset (CFO) and sampling-frequency offset (SFO) are embedded in the phase rotations of the complex frequency-domain signal components at the output of the fast Fourier transform (FFT). To extract the phase rotations and estimate the CFO and SFO, the frequency-domain signal components need to be known. However, they are, in general, not known to the receiver, since they are a mixture of the data and pilot symbols. To solve this difficulty sub-block processing is proposed, such that joint estimation of the CFO and SFO can be applied. For the joint estimation, both the linear least-squares (LLS) and simple weighted least-squares (SWLS) regressions are considered, where the latter is shown to be robust to the channel frequency-selectivity. Finally, the SC-FDE receiver with proposed closed-loop tracking algorithm is tested on both quasi-static and time-varying multipath fading channels and its effectiveness is demonstrated.
01 Jan 2007
TL;DR: Results show that under additive white Gaussian noise and multi-path fading channels, the mean and the square mean data of timing estimation using the algorithm are consistent with data under the ideal channel.
Abstract: Aimed at inter-symbol interferences easily caused by the symbol timing offset in single carrier modulation systems with frequency domain equalization (SC-FDE),a novel algorithm for symbol timing synchronization was proposedAccording to the recommended frame structure of IEEE80216,the independent correlation of multiple preambles and the unique words(UW) in data sequence were adopted in the algorithm,and the initial timing offset was estimatedThe timing offset tracking loop was performed by an interpolator and then timing synchronization was acquiredThe computer simulation results show that under additive white Gaussian noise and multi-path fading channels,the mean and the square mean data of timing estimation using the algorithm are consistent with data under the ideal channelThe present probability of timing estimation offset converges at the precise positionThe proposed algorithm can achieve more accurate symbol timing synchronization compared with the conventional timing method,and doesn't need more computing resource of the system
17 Dec 2007
TL;DR: In this paper, the authors apply the derivation of an optimal pre-and post processing to a single carrier system with frequency domain equalization (SC/FDE) and show a performance gain of up to 8 dB at a bit error rate of 10-5.
Abstract: Noise represents a major performance limiting factor for wireless communication systems. Pre-and post processing of the transmitted information enables to reduce the influence of noise significantly, leading to a severe performance gain. We apply the derivation of an optimal pre-and post processing to a single carrier system with frequency domain equalization (SC/FDE). Comparisons between the standard SC/FDE system with a zero-forcing equalizer and the enhanced system show a performance gain of up to 8 dB at a bit error rate of 10-5.
TL;DR: In this paper, the decoder output is incorporated in the process of equalization, i.e., the Turbo equalizer is employed, which not only recovers the performance loss due to insufficiency of CP, but also provides extra gains over the lower bound of performance for conventional CP reconstruction schemes.
Abstract: In this paper, a Turbo aided Cyclic Prefix (CP) reconstruction scheme, termed Turbo-CPR, is proposed for Single-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient CP in the transmitter. In Turbo-CPR, the decoder output is incorporated in the process of equalization, i.e. Turbo equalizer is employed. It is shown in the simulation results that Turbo-CPR not only recovers the performance loss due to insufficiency of CP, but also provides extra gains over the lower bound of performance for conventional CP reconstruction schemes.
08 Oct 2007
TL;DR: An improved decoding method for regular low density parity check (LDPC) codes is proposed to compensate for the loss in signal-to-noise (SNR) due to the CP insertion.
Abstract: Single carrier transmission with cyclic prefix (SC-CP or SC-FDE), has been adopted in wireless applications as an alternative technique to orthogonal frequency division multiplexing (OFDM). In this paper, an improved decoding method for regular low density parity check (LDPC) codes is proposed to compensate for the loss in signal-to-noise (SNR) due to the CP insertion. According to our research, the algorithm to select suitable CP plays an important role in decoding. The performance of the uncoded case is well analyzed. Simulation results show that the proposed scheme is effective under both AWGN and Rayleigh fading channels.
TL;DR: The semi-analytical analysis yields fairly accurate bit error rate performance, thus validating the use of the Gaussian approximation method in the performance analysis of the SC-FDE system with channel estimation error.
Abstract: Single carrier block transmission with frequency domain equalization (SC-FDE) has been shown to be a promising candidate in ultra-wideband (UWB) communications. In this paper, we analyze the performance of SC-FDE over UWB communications with channel estimation error. The probability density functions of the frequency domain minimum mean-squared error (MMSE) equalizer taps are derived in closed form. The error probabilities of single carrier block transmission with frequency domain MMSE equalization under imperfect channel estimation are presented and evaluated numerically. Compared with the simulation results, our semi-analytical analysis yields fairly accurate bit error rate performance, thus validating the use of the Gaussian approximation method in the performance analysis of the SC-FDE system with channel estimation error.
TL;DR: The energy spreading transform is designed, a precoder that enables iterative reconstruction of missing cyclic prefix and the performance of the proposed scheme is shown to be close to that of SC-FDE with enough length of Cyclic prefix.
Abstract: A cyclic prefix reconstruction scheme is proposed for precoded single-carrier systems with frequency-domain equalization (SC-FDE) that employ insufficient length of cyclic prefix. For SC-FDE, cyclic prefix is employed to facilitate frequency-domain equalization at the receiver. Since inserting cyclic prefix incurs a loss in bandwidth-utilization efficiency, it is desirable to limit the length of cyclic prefix for SC-FDE. This paper designs the energy spreading transform (EST), a precoder that enables iterative reconstruction of missing cyclic prefix. The performance of the proposed scheme is shown to be close to that of SC-FDE with enough length of cyclic prefix.
TL;DR: In this paper, an efficient cyclic prefix reconstruction scheme is proposed for single-carrier systems with Frequency Domain Equalization (SC-FDE) that employ insufficient length of CP at the transmitter.
Abstract: In this paper, an efficient Cyclic Prefix (CP) reconstruction scheme is proposed for Single-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient length of CP at the transmitter. By utilizing a decision feedback filter to cancel the residual InterSymbol Interference (ISI) in the equalized signal, the proposed scheme can effectively lower the low bound of performance for the CP reconstruction schemes and can greatly improve the Bit Error Rate (BER) performance of SC-FDE systems. In addition, the existing methods and the proposed scheme are also optimized. It is shown in the simulation results that, when the Signal-to-Noise Ratio (SNR) exceeds a certain threshold, the proposed scheme can achieve the low bound of performance for the existing methods. Moreover, by increasing the number of iteration or through optimization, the low bound can be outperformed.
TL;DR: By applying the proposed method to the multi-antenna SC-FDE system with insufficient cyclic prefix (CP), the method can significantly improve its error performance, obtaining the benefits of spectral efficiency gain and multiplexing/diversity gain in MIMO/STBC/SFBC.
Abstract: In this paper, an efficient cyclic prefix reconstruction (CPR) technique with turbo equalization is developed for multi-antenna single-carrier frequency-domain equalization (SC-FDE) systems, which are for multi-input multi-output (MIMO), space-time block code (STBC), and space-frequency block code (SFBC) applications. The proposed method includes pre-processing estimation (PPE), weighted interblock interference cancellation (WIBIC), or residual intercarrier interference suppression (RICIS). PPE is employed to compute initial values of MIMO turbo equalization and the WIBIC is developed to cancel interblock interference (IBI) at the initial iteration of the CPR for STBC SC-FDE. RICIS is used to mitigate residual intercarrier interference (ICI) after each iteration of the CPR. By applying the proposed method to the multi-antenna SC-FDE system with insufficient cyclic prefix (CP), we can significantly improve its error performance, obtaining the benefits of spectral efficiency gain and multiplexing/diversity gain in MIMO/STBC/SFBC.