Seung Hee Han

One of the main drawbacks of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) of the OFDM signal. In this paper, we propose the use of hexagonal constellation for PAPR reduction of an OFDM signal. Because hexagonal constellation is the densest packing of regularly spaced points in two dimensions, we c...

One of the main drawbacks of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) of the OFDM signal. Tone injection (TI) technique is a promising candidate for the reduction of the PAPR of an OFDM signal. But this technique requires the increase of the transmit signal power because of the injected signal...

High peak-to-average power ratio (PAPR) of the transmit signal is a major drawback of orthogonal frequency division multiplexing (OFDM). Selected mapping (SLM) technique is an efficient PAPR reduction technique for OFDM. In the SLM technique, many data blocks are generated from an OFDM data block using a set of phase sequences, and then the one wit...

High peak-to-average power ratio of the transmit signal is a major drawback of multicarrier transmission such as OFDM or DMT. This article describes some of the important PAPR reduction techniques for multicarrier transmission including amplitude clipping and filtering, coding, partial transmit sequence, selected mapping, interleaving, tone reserva...

A major drawback of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) of the transmitted signal. Partial transmit sequence (PTS) technique can improve the PAPR statistics of OFDM signals. In the PTS technique, the data block to be transmitted is partitioned into disjoint subblocks and the subblocks are...

High peak-to-average power ratio (PAPR) of the transmitted signal is a major drawback of orthogonal frequency division multiplexing (OFDM). The selected mapping (SLM) technique is one of the promising PAPR reduction techniques for OFDM. In the SLM technique, some statistically independent data blocks are generated from an OFDM data block using a se...

High peak-to-average power ratio (PAPR) of the transmitted signal is a major drawback of orthogonal frequency division multiplexing (OFDM). In this paper, we propose a modified selective mapping (SLM) technique for PAPR reduction of coded OFDM signal. In this technique, we embed the phase sequence, which is used to lower the PAPR of the data block,...

A major drawback of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) of the transmitted signal. In this paper, we propose a novel technique to reduce PAPR in an OFDM signal. Proposed technique is based on signal set expansion. Each point in the original signal set is associated with two or more points...

In this letter, we propose a groupwise successive interference cancellation (GSIC) receiver with gradient descent search for multirate DS-CDMA system. Proposed receiver incorporates iterative gradient descent search algorithm into conventional GSIC receiver for multi-rate DS-CDMA system. It is shown that the receiver achieves significant performanc...

One of the main drawbacks of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) of the transmitted OFDM signal. Partial transmit sequence (PTS) technique can improve the PAPR statistics of an OFDM signal. In the PTS technique, the data block to be transmitted is partitioned into disjoint sub-blocks and...

In this letter, we present groupwise successive interference cancellation (GSIC) receiver with adaptive minimum mean squared error (MMSE) detection and extended GSIC (EGSIC) receiver with adaptive MMSE detection for dual-rate DS-CDMA system. The receivers are GSIC receiver and EGSIC receiver combined with adaptive MMSE detection which is introduced...

In a multi-rate DS-CDMA system with multiple modulation, modulation format is adjusted according to the data rate of each user while symbol duration is fixed for all users. In this paper, two types of multi-stage partial parallel interference cancellation (PIC) receivers are considered for multi-rate DS-CDMA system with multiple modulation: multi-s...

One of the main drawbacks of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) of the transmitted OFDM signal. Partial transmit sequence (PTS) technique can improve the PAPR statistics of an OFDM signal. In the PTS technique, the data block to be transmitted is partitioned into disjoint sub-blocks and...

In this paper, two types of multi-stage partial parallel interference cancellation (PIC) receivers are considered for multi-rate DS-CDMA system: multi-stage PIC receiver with partial cancellation factors and multi-stage PIC receiver with decision thresholds. Bit error rate (BER) of the multi-stage partial PIC receivers is obtained by simulation in...

In this paper, group-wise successive interference cancellation (GSIC) receiver with adaptive minimum mean squared error (MMSE) detection and extended GSIC (EGSIC) receiver with adaptive MMSE detection are proposed for dual-rate DS-CDMA system. Users are divided into 2 groups for their data rates: high-rate (HR) users and low-rate (LR) users. Initia...

An objective function based group-wise successive interference cancellation (GSIC) receiver is proposed for a dual-rate DS-CDMA system. In the receiver, user signals are divided into 2 groups for their data rates. Initial bit estimates for the users in group 1 are obtained by its matched filter (MF) bank. The initial bit estimates for the group 1 u...

An adaptive multi-stage parallel interference cancellation (PIC) receiver is considered for a multi-rate DS-CDMA system. In each stage of the adaptive multi-stage PIC receiver, multiple access interference (MAI) estimates are obtained using the sub-bit estimates from the previous stage and the adaptive weights for the sub-bit estimates. The adaptiv...

A multi-stage partial parallel interference cancellation receiver is proposed for the multi-rate DS-CDMA system which adopts the multiple processing gain scheme. In each stage of the proposed receiver, partial cancellation is performed with an adaptive decision threshold which is computed from the matched filter outputs of the previous stage. The B...

SUMMARY In this paper, two types of multi-stage partial parallel interference cancellation (PIC) receivers are considered for multi-rate DS-CDMA system: multi-stage PIC receiver with partial cancellation factors and multi-stage PIC receiver with de- cision thresholds. Bit error rate (BER) of the multi-stage par- tial PIC receivers is obtained by si...