Analysis of Baseband IQ Data Compression Methods for Centralized RAN

Through recent wireless technologies, such as Centralized Radio Access Network, baseband unit aid remote radio heads are physically separated and connected using fronthaul links. Compressing complex baseband signal samples prior transmission over fronthaul link is an effective Way to satisfy the pressing need to decrease the huge required transported data rates. In this paper, we analyze the easting IQ data compression schemes exploiting time and spectral signal characteristics. We consider compression system evaluation parameters to have a smooth trade-off between required signal quality and complexity performance while achieving an acceptable compression gain. We propose an optimized uniform quantization technique combined with entropy coding achieving non-uniform quantization performance by exploiting signal temporal statistical characteristics with much less computational complexity. We also present a comparison between simulation results analyzing the trade-off between the removal of the signal spectral redundancies and vector quantization in terms of performance and complexity.

[1]  C-ran the Road towards Green Ran , 2022 .

[2]  Boon Loong Ng,et al.  A Novel and Efficient Vector Quantization Based CPRI Compression Algorithm , 2017, IEEE Transactions on Vehicular Technology.

[3]  Herbert Gish,et al.  Asymptotically efficient quantizing , 1968, IEEE Trans. Inf. Theory.

[4]  R. Ladner Entropy-constrained Vector Quantization , 2000 .

[5]  Robert M. Gray,et al.  An Algorithm for Vector Quantizer Design , 1980, IEEE Trans. Commun..

[6]  Allen Gersho,et al.  Vector quantization and signal compression , 1991, The Kluwer international series in engineering and computer science.

[7]  Ding Peng-ren,et al.  Compressed transport of baseband signals in cloud radio access networks , 2014, 9th International Conference on Communications and Networking in China.

[8]  Wei Cao,et al.  LTE/LTE-A signal compression on the CPRI interface , 2013, Bell Labs Technical Journal.

[9]  S. P. Lloyd,et al.  Least squares quantization in PCM , 1982, IEEE Trans. Inf. Theory.

[10]  Miguel Berg,et al.  Improved LPC-Based Fronthaul Compression With High Rate Adaptation Resolution , 2018, IEEE Communications Letters.

[11]  Miguel Berg,et al.  An LPC-Based Fronthaul Compression Scheme , 2017, IEEE Communications Letters.

[12]  Joseph R. Cavallaro,et al.  Baseband signal compression in wireless base stations , 2012, 2012 IEEE Global Communications Conference (GLOBECOM).

[13]  Reinaldo A. Valenzuela,et al.  Ieee Transactions on Wireless Communications, Accepted for Publication Compressed Transport of Baseband Signals in Radio Access Networks , 2022 .

[14]  T. Cover,et al.  Rate Distortion Theory , 2001 .

[15]  David A. Huffman,et al.  A method for the construction of minimum-redundancy codes , 1952, Proceedings of the IRE.