Combined trellis shaping and coding to control the envelope of a bandlimited PSK-signal

2009 IEEE International Conference on Communications

2009

Single-carrier (SC) transmission is considered as a promising candidate for the uplink of the next generation cellular systems due to its relatively low peak-to-average power ratio (PAR) compared to multi-carrier systems such as orthogonal frequency division multiplexing (OFDM). In SC systems, bandwidth efficiency can be effectively enhanced by the use of waveform shaping filter with low roll-off factor. However, as a price, nonnegligible increase of PAR is incurred in pulse-shaped signals even for phase shift keying (PSK) modulation. To balance both low PAR and high bandwidth efficiency, the authors have recently proposed a novel PAR reduction technique for SC-PSK based on trellis shaping (TS). In this paper, we evaluate its effectiveness and feasibility through implementation with field programmable gate array (FPGA) and testbed experiments with a sample RF power amplifier (PA).

Section: Introductionmentioning

confidence: 99%

FPGA Implementation of Trellis Shaping to Control Peak Power for PSK Signals

Kitagawa

2009 IEEE International Conference on Communications

2009

“…The original TS introduced by Forney [5] was not intended to be used as a PAR reduction scheme, but TS-based PAR reduction approaches have been subsequently studied for SC signal application in [6][7][8] and for OFDM in [9][10][11]. The pioneering work by Morrison [6], however, does not offer significant reduction of PAR due to its empirical shaping metric design.…”

Section: Introductionmentioning

confidence: 99%

Trellis Shaping for Controlling Envelope of Single-Carrier High-Order QAM Signals

IEEE J. Sel. Top. Signal Process.

2009

Abstract-In this paper, trellis shaping (TS) is applied to dynamic range control of band-limited single-carrier high-order quadrature amplitude modulation (QAM) signals. With a newly designed shaping metric, we show that a signal with very low peak-to-average power ratio (PAR) can be achieved without significant loss of data rate. A specific example demonstrates that a band-limited transmission with spectral efficiency of 4.55 bit/sec/Hz (including the redundancy due to the shaping) and PAR below 3 dB is achievable using a square 64-ary QAM constellation and a root raised-cosine filter with a roll-off factor 0.1. Furthermore, the proposed TS for high-order QAM can simultaneously reduce the average power and thus offers a shaping gain. The reduction of the PAR and average power can be flexibly controlled by adjusting a parameter associated with the shaping process.

“…Similar to the concept of multidimensional trellis coded modulation (TCM), the TS with d > 1 is generally referred to as multidimensional shaping [5,7].…”

Section: −1 Smentioning

confidence: 99%

“…This technique has been successively applied to a PAR reduction of single carrier systems by Morrison [4] and further studied in [5]. More recently, it has been applied to the PAR reduction of multicarrier and OFDM systems in [6,7].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Near constant envelope trellis shaping for PSK signaling

2009

IEEE Trans. Commun.

In this paper, we propose a powerful trellis shaping for peak-to-average power ratio (PAR) reduction of pulse-shaped phase shift keying (PSK) systems. The proposed approach consists of 1) memory extension of trellis shaping encoder for capturing the full effect of pulse shaping filter impulse response, and 2) simple branch metrics that quantify envelope fluctuation of the filter output. Simulation results demonstrate that achieving near constant envelope is possible even if a pulse shaping filter with roll-off factor as low as 0.1 is employed. Furthermore, due to the circular nature of the resulting signal trajectory, the proposed system also exhibits a robustness against sampling timing jitter at the receiver. Index TermsBand-limited single-carrier communications, peak-to-average power ratio reduction, trellis shaping